JP4731808B2 - Image display device - Google Patents

Description

  The present invention relates to an image display device that displays an image by projecting an optical image signal given image information onto a display means, and also relates to an alignment adjustment method for optical system components used in the image display device. Is.

  FIG. 95 is a diagram showing a configuration of a conventional image display apparatus. 1 is a light-emitting body that outputs light, 2 is a parabolic reflector that reflects light output from the light-emitting body 1 so as to be substantially parallel, and 3 is a collector that collects light reflected by the parabolic reflector 2. It is a light lens. An illuminating light source system is composed of the light emitter 1, the paraboloid reflector 2, and the condenser lens 3.

  4 is a light valve that spatially modulates the intensity of the light collected by the condenser lens 3 based on image information, 5 is a projection optical lens that projects the light whose intensity is modulated by the light valve 4 onto the screen 6, and 6 It is a screen that displays the light projected from the projection optical lens 5 as an image. The optical path is indicated by an arrow.

Next, the operation will be described.
The light output from the light emitter 1 is reflected by the paraboloid reflector 2 and collected by the condenser lens 3 onto the light valve 4. The light valve 4 spatially modulates the intensity of the collected light based on the image information. The intensity-modulated light is projected onto the screen 6 from the rear (left side in FIG. 95) by the projection optical lens 5 and displayed as an image. A user of the image display device visually recognizes an image from the front of the screen 6 of FIG. 95 (right side of FIG. 95).

  The depth of the image display device in FIG. 95 corresponds to the distance from the illumination light source system including the light emitter 1, the paraboloid reflector 2, and the condenser lens 3 to the screen 6. In the case of an image display device capable of displaying an image of the same size, it is preferable that the depth is as thin as possible. For this reason, in the conventional image display apparatus shown in FIG. 95, an image is displayed on the screen 6 using the wide-angle projection optical lens 5 so that the depth of the image display apparatus can be suppressed as much as possible. Yes.

  However, since the wide angle of the projection optical lens 5 is limited, in order to further reduce the thickness of the image display device of FIG. 95, a plane mirror 7 inclined by 45 ° with respect to the horizontal direction is provided as shown in FIG. The optical path from the projection optical lens 5 is bent and projected onto the screen 6.

  In the image display device of FIG. 96, the constituent elements of the illumination light source system, the light valve 4 and the projection optical lens 5 are arranged in the height direction of the image display device (vertical direction in FIG. 96), thereby reducing the thickness of the image display device. It is possible. The depth of the image display device in this case corresponds to the distance from the plane mirror 7 to the screen 6. If the inclination of the plane mirror 7 with respect to the horizontal direction is made larger than 45 °, the image display device can be further thinned. However, the light valve 4 and the light source part interfere with the projection light, and the light is scattered and the screen 6 The optical path is lost.

  Further, Patent Document 1 discloses an image display device that uses a convex mirror instead of the plane mirror 7 in FIG. 96 to reflect light and display an enlarged image on the screen 6. Will be displayed.

JP-A-6-11767

  Since the conventional image display apparatus is configured as described above, there is a limit to reducing the thickness of the image display apparatus, and there is a problem that it cannot be reduced further.

  The present invention has been made to solve the above-described problems, and an image display device capable of displaying an enlarged image without distorting the image and further reducing the thickness of the image display device as compared with the prior art. With the goal.

  Another object of the present invention is to provide an alignment adjustment method for adjusting the alignment of optical system components of the image display device.

An image display device according to the present invention includes a light emitter that emits light, a spatial light modulator that emits light after modulating incident illumination light according to image information, and guides light emitted from the light emitter to the spatial light modulator. Condensing means for making it incident as illumination light, transmitting image information to illumination light and transmitting it as an optical image signal, a reflecting part for reflecting the optical image signal, and correcting the aberration of the reflecting part A projection optical unit configured to project the optical image signal onto the reflection unit, and a projection optical unit configured to project the optical image signal; and a display configured to receive the optical image signal via the projection optical unit and display an image based on the image information. and means, the optical axis of the projection optical hand stage is obtained so as to be positioned outside a display unit.

In the image display device according to the present invention, at least a part of the transmission unit is an optical image signal that is a space on the light receiving surface side of the display unit and on one side of the optical axis, and reflected by the reflection unit. It is arranged in an unobstructed space.

The image display apparatus according to the present invention includes a plane mirror that reflects the optical image signal from the projection optical unit to the display unit, and the light receiving surface of the display unit and the reflection surface of the plane mirror are in a parallel relationship, A first point that has a bottom surface orthogonal to the reflecting surface of the plane mirror and the light receiving surface of the display means, is present on the base of the quadrangular image displayed on the display means, and is farthest from the center of the image A second point on the plane mirror where the light beam toward the first point is reflected, a third point on the reflector where the light beam toward the second point is reflected, and the first point The fourth point, the fifth point, and the sixth point, which are points projected from the normal direction of the bottom surface to the bottom surface, the second point, and the third point. The main part of the condensing optical system consisting of the light emitter and a part of the condensing means is arranged in the pentahedron-shaped arrangement space Is obtained by way it is.

In the image display device according to the present invention, the projection optical unit includes a first optical path bending unit that reflects an optical image signal from the refractive optical unit to the reflection unit.

In the image display device according to the present invention, the first optical path bending means bends the optical axis direction of the refractive optical unit in a horizontal plane including the optical axis of the reflecting unit.

In the image display device according to the present invention, a reflecting mirror or a prism element is used as the first optical path bending means.

In the image display device according to the present invention, the refractive optical unit includes second optical path bending means for reflecting an optical image signal from the first lens means to the second lens means.

In the image display device according to the present invention, a reflecting mirror or a prism element is used as the second optical path bending means.

In the image display device according to the present invention, the reflecting part is formed by cutting out a non-reflecting part that does not reflect the optical image signal to the display means.

In the image display device according to the present invention, the optical axis of the main part of the condensing optical system is arranged in parallel to the light receiving surface and the bottom surface of the display means.

In the image display device according to the present invention, the optical axis of the main part of the condensing optical system is installed in parallel to the light receiving surface of the display means, and is inclined at a predetermined angle with respect to the bottom surface. is there.

The image display device according to the present invention mediates a light beam emitted from the main part of the condensing optical system and incident on the spatial light modulation element, and a light beam emitted from the spatial modulation element and incident on the refractive optical part. The second prism element is provided.

According to the present invention, a light emitting body that emits light, a spatial light modulation element that modulates incident illumination light according to image information and emits the light, and the light emitted from the light emitting body is guided to the spatial light modulation element and incident as illumination light. And a condensing unit for transmitting the image information to the illumination light and transmitting it as an optical image signal, a reflecting unit for reflecting the optical image signal, and correcting the aberration of the reflecting unit, and correcting the optical image signal. A projection optical unit configured to project an optical image signal; and a display unit configured to receive the optical image signal through the projection optical unit and display an image based on the image information. since the optical axis of the projection optical hand stage is arranged at a position deviated from the display means, it is not necessary to separately provide an optical component for bending the optical path to the display means, the display means to reduce the number of optical components reflected Department and It is possible to shorten the distance between, also there is an advantage that it is possible to configure the image display device thinner.

According to the present invention, at least a part of the transmission unit is a space on the light receiving surface side of the display unit and on one side of the optical axis, and a space that does not block the optical image signal reflected by the reflection unit. Therefore, an effect that a thin image display device can be configured is obtained.

According to this invention, the flat mirror for reflecting the optical image signal from the projection optical means to the display means is provided, the light receiving surface of the display means and the reflective surface of the flat mirror are in a parallel relationship, and A first point that has a reflecting surface and a bottom surface orthogonal to the light receiving surface of the display means, exists on the bottom of a quadrilateral image displayed on the display means, and is farthest from the center of the image; A second point on the plane mirror where the light beam toward the first point is reflected; a third point on the reflector where the light beam toward the second point is reflected; and the first point; The second point, the fifth point, and the sixth point, which are points obtained by projecting the second point and the third point onto the bottom surface from the normal direction of the bottom surface, are the 5 points. The main part of the condensing optical system consisting of the light emitter and a part of the condensing means is arranged in the arrangement space in the shape of a plane. Since, in a thin range of the image display apparatus defined by the display means and a plane mirror, the effect is obtained that the height of the bottom of the screen can be suppressed.

According to the present invention, the projection optical means includes the first optical path bending means for reflecting the optical image signal from the refractive optical section to the reflection section. An effect is obtained that an image display device with a lower lower portion can be configured.

According to the present invention, since the first optical path bending means bends the optical axis direction of the refractive optical unit in a horizontal plane including the optical axis of the reflecting unit, the thickness of the first optical path bending unit is further reduced and the lower portion of the screen The effect that the image display apparatus which restrained height low can be comprised is acquired.

According to the present invention, since the reflecting mirror or the prism element is used as the first optical path bending means, the degree of freedom is given to the control of the light beam by devising the curved reflecting surface or refracting surface. As a result, various optical performances can be improved.

According to this invention, since the refractive optical unit includes the second optical path bending means for reflecting the optical image signal from the first lens means to the second lens means, the image display device is made thinner. Thus, an effect is obtained that it is possible to configure an image display device in which the lower portion of the screen is kept low.

According to this invention, since the reflecting mirror or the prism element is used as the second optical path bending means, the degree of freedom is given to the control of the light beam by devising the curved reflecting surface or refracting surface. As a result, various optical performances can be improved.

According to this invention, since the reflection part has a shape in which the non-reflection part that does not reflect the optical image signal to the display means is cut out, the reflection part is made smaller by the amount of the non-reflection part cut out. Thus, the cost of the image display apparatus can be reduced, and the configuration space inside the image display apparatus can be effectively used.

According to the present invention, since the optical axis of the main part of the condensing optical system is arranged in parallel to the light receiving surface and the bottom surface of the display means, the screen without shortening the life of the illumination light source unit The effect that the image display apparatus which can respond | correspond to various utilization forms by suppressing the height of a lower part can be acquired.

According to this invention, the optical axis of the main part of the condensing optical system is installed in parallel to the light receiving surface of the display means and is inclined at a predetermined angle with respect to the bottom surface. Without shortening the life of the image display device, it is possible to configure an image display device that can cope with various usage modes by suppressing the height of the lower portion of the screen.

According to this invention, the second light beam that mediates the light beam emitted from the main part of the condensing optical system and incident on the spatial light modulation element and the light beam emitted from the spatial modulation element and incident on the refractive optical part. Since the prism element is provided, the light can be condensed by the main part of the condensing optical system arranged in the arrangement space with respect to the reflective light spatial modulation element, and reflected by the spatial light modulation element. An effect is obtained that the degree of freedom of the configuration for separating the obtained light beam from the incident light beam to the spatial light modulator can be increased.

Hereinafter, an embodiment of the present invention will be described.
Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of an image display apparatus according to Embodiment 1 of the present invention. 11 is a light emitter that emits light (illumination light), 12 is a paraboloid reflector that reflects light emitted from the light emitter 11 so as to be approximately parallel, and 13 is a light that collects light reflected from the paraboloid reflector 12. It is a condensing lens. An illuminating light source system (transmitting means, illuminating light source unit) is composed of the light emitter 11, the parabolic reflector 12, and the condenser lens 13.

  14 is a micromirror device (transmission means, reflection-type image information assigning unit, digital micromirror device, abbreviated as DMD, a registered trademark of Texas Instruments Incorporated (TI)), which is a reflection-type spatial light modulation element. 14 spatially modulates the intensity of the light collected by the condenser lens 13 by its reflecting surface, and reflects the intensity-modulated light as an optical image signal to which image information is given. The present invention can be applied to an image display apparatus including any light spatial modulation element, but will be described below using the micromirror device 14. Reference numeral 15 denotes a refractive optical lens (refractive optical part) having barrel distortion (correction aberration), 16 denotes a convex mirror (reflecting part) having pincushion distortion, and 17 denotes a projection composed of the refractive optical lens 15 and the convex mirror 16. It is an optical system (projection optical means). The projection optical system 17 projects light spatially modulated by the micromirror device 14 onto the screen 18. The light modulated by the micromirror device 14 is projected onto the convex mirror 16 by the refractive optical lens 15. reflect. The reflecting surface of the convex mirror 16 has a negative power, and enlarges and projects an image of incident light on the screen 18. Reference numeral 18 denotes a screen (display means) that receives light projected from the projection optical system 17 and displays an image. The optical path is indicated by an arrow.

  In the first embodiment, the reflection surface of the micromirror device 14 and the light-receiving surface of the screen 18 are arranged in parallel so that the depth of the image display device is minimized. Further, the micromirror device 14 and the screen 18 are arranged so as not to overlap in the height direction so that the projected light is not shattered. Further, the projection optical system 17 is arranged so that the conjugate relationship between the image of the micromirror device 14 and the image of the screen 18 is maintained while satisfying the arrangement condition of the micromirror device 14 and the screen 18.

Next, the operation will be described.
The light output from the light emitter 11 is reflected by the paraboloid reflector 12 and enters the reflecting surface of the micromirror device 14 from an oblique direction via the condenser lens 13. The micromirror device 14 spatially modulates the intensity of incident light based on image information. The intensity-modulated light is projected onto the screen 18 by the projection optical system 17 to display an image. A user of the image display device visually recognizes an image from the left side of the screen 18 in FIG.

Here, the micromirror device 14 will be described.
The micromirror device 14 has a reflecting surface in which small mirrors of 16 μm square are arranged in a two-dimensional array at a pitch of 17 μm, and the small mirrors and the image format normally correspond one to one. For example, the inclination of each small mirror can be individually changed by a voltage applied from a controller (not shown), and the direction of reflected light from each small mirror can be changed.

  That is, when the reflected light from a certain small mirror is projected onto the screen 18, the inclination of the corresponding small mirror is changed so that the light is reflected in the direction of the opening of the projection optical system 17. In addition, when the reflected light from a certain small mirror is not projected onto the screen 18, the inclination of the corresponding small mirror is controlled so that the light is reflected in a direction away from the opening of the projection optical system 17. The time required to change the tilt of the small mirror is 10 μsec or less, and the micromirror device 14 can modulate the intensity of light at high speed.

  Since the micromirror device 14 is a reflective spatial light modulation element, it is possible to modulate the intensity of light incident from an oblique direction with respect to the reflection surface and reflect the light. For example, when liquid crystal is used as the light spatial modulation element, light must be incident substantially perpendicularly from the back surface of the liquid crystal, so that the thinning of the image display device is restricted by the illumination light source system disposed on the back surface. Therefore, the effectiveness of the micromirror device 14 becomes clear. By using the micromirror device 14 as in the first embodiment, a convex mirror that arranges an illumination light source system on the side from which the micromirror device 14 emits light and bends the optical path to the light spatial modulation element and the screen 18. It is possible to arrange the illumination light source system between 16, effectively use the space in the height direction of the image display device, and prevent the illumination light source system from overhanging.

Next, the projection optical system 17 will be described.
The light whose intensity is modulated by the micromirror device 14 is reflected to the projection optical system 17. As shown in FIG. 1, the optical axis of the refractive optical lens 15 is perpendicular to the reflecting surface of the micromirror device 14 and the light receiving surface of the screen 18, and is offset from the center of the micromirror device 14 and the center of the screen 18. Installed. Therefore, only a part of the angle of view of the refractive optical lens 15 is used for projecting light from the micromirror device 14. In FIG. 1, since light is incident from below the refractive optical lens 15, the light is emitted upward.

  FIG. 2 is a diagram conceptually illustrating an operation in which the barrel distortion of the refractive optical lens 15 corrects the pincushion distortion of the convex mirror 16. As shown in FIG. 2, the refractive optical lens 15 is designed to have barrel distortion, and light indicating a lattice-like image (FIG. 2A) from the micromirror device 14 to the refractive optical lens 15. When projected, the lattice-shaped image is deformed into a barrel shape (FIG. 2B). This barrel distortion is a characteristic (correction aberration) for correcting the pincushion distortion (FIG. 2C) generated in the convex mirror 16, and is designed based on the pincushion distortion of the convex mirror 16. .

  Therefore, when the light whose distortion is corrected is projected onto the screen 18, the enlarged lattice-like image (FIG. 2D) is displayed without distortion. In general, it is possible to correct image distortion caused by an optical system by signal processing. However, since the definition of the image deteriorates, in the first embodiment, distortion is optically corrected. I have to.

Here, the pincushion distortion of the convex mirror 16 will be described.
FIG. 3 is a diagram conceptually showing a method of obtaining an image by optical path tracking when light from the micromirror device 14 is reflected by the convex mirror 16 or the plane mirror 21 via the aberration-free refractive optical lens 19. In FIG. 3, the optical path reflected by the plane mirror 21 is indicated by a solid line, and the optical path reflected by the convex mirror 16 is indicated by a broken line.

  When light having a lattice-like image (FIG. 3A) is emitted from the micromirror device 14, the image of the light transmitted through the non-aberration refractive optical lens 19 is not distorted (FIG. 3B). Therefore, when the light transmitted through the refracting optical lens 19 having no aberration is reflected by the plane mirror 21 and observed on the AA ′ cross section perpendicular to the optical axis 20 of the refractive optical lens 19, black dots (●) are equally spaced. It exists (FIG. 3 (d)). In other words, in the case of a projection optical system composed of the aberration-free refractive optical lens 19 and the plane mirror 21, no distortion is shown while maintaining a lattice-like image.

  On the other hand, when the light transmitted through the non-aberration refracting optical lens 19 is reflected by the convex mirror 16, the reflection position in the optical axis direction on the reflection surface of the convex mirror 16 is different for each optical path. Then, as indicated by white circles (◯), pincushion distortion (FIG. 3C) occurs. Since this pincushion distortion can be calculated by optical path tracking when the shape of the convex mirror 16 is determined, the distortion of the refractive optical lens 15 in FIG. 1 may be designed based on the calculation result. The distortion design method is omitted here because it may be performed based on the design of a conventional refractive optical system.

  As described above, since the refractive optical lens 15 is used so as to have barrel distortion that corrects the pincushion distortion of the convex mirror 16, an image without distortion can be enlarged and displayed on the screen 18. The position of the screen 18 with respect to each component of the apparatus can be configured to be suitable for thinning.

  The convex mirror 16 can be easily manufactured by a mirror lathe by forming a rotating aspheric surface obtained by rotating a quadratic curve around an axis into the shape of the reflecting surface, thereby greatly reducing the manufacturing cost. it can. The convex mirror 16 can be freely designed according to the specifications of the image display device, and the refractive optical lens 15 having a barrel distortion that corrects the pincushion distortion of the designed convex mirror 16 may be designed.

  In the prior art, a means for bending the optical path is required separately from the projection optical system 17 as in the plane mirror 7 of FIG. 96. In the first embodiment, a part of the projection optical system 17 bends the optical path. Since it also has an action, the number of optical components is reduced, and the distance between the screen 18 and the convex mirror 16 can be shortened.

  Further, as shown in FIG. 4, when the illumination light source system protrudes greatly, a plane mirror 22 that reflects light from the projection optical system 17 is added to bend the optical path to the screen 18. Thus, the space of the image display device can be utilized to the maximum. The plane mirror 22 and the projection optical system 17 may be interchanged, and a projection optical system different from the projection optical system 17 may be used instead of the plane mirror 22.

  As described above, according to the first embodiment, the illumination light source system and the micromirror device 14 are configured to transmit a light image signal whose intensity is modulated based on image information, and to receive the light image signal. A screen 18 for displaying an image based on the image information, a convex mirror 16 having negative power and reflecting light whose intensity is modulated based on the image information to the screen 18, and a pincushion distortion aberration of the convex mirror 16. Since the refractive optical lens 15 having a barrel distortion to be corrected and installed so as to project the light from the transmitting unit onto the convex mirror 16 is provided, the light modulated based on the image information is projected to the convex mirror 16. Accordingly, the enlarged image can be displayed on the screen 18 by correcting the pincushion distortion received from the screen 18 and the screen 18 is arranged at the optimum position for thinning the image display device. It is possible to effect that it is possible to construct more image display device thinner than the conventional can be obtained.

  Further, according to the first embodiment, the illumination light source system composed of the light emitter 11, the paraboloid reflector 12, and the condenser lens 13 and the light incident from the illumination light source system are modulated based on the image information. Since the transmitting means is constituted by the reflecting micromirror device 14, the illumination light source system can be arranged on the side from which the micromirror device 14 emits light, and a transmission type spatial light modulating element such as liquid crystal is provided. As compared with the conventional image display device used, an effect that a thinner image display device can be obtained is obtained.

  Further, according to the first embodiment, since the light reflected from the micromirror device 14 is reflected to the screen 18 by the projection optical system 17, it is necessary to separately provide an optical component for bending the optical path to the screen 18. Thus, the effect of reducing the number of optical components and shortening the distance between the screen 18 and the convex mirror 16 can be obtained.

  Furthermore, according to the first embodiment, since the convex mirror 16 has a rotating aspherical shape, it can be easily manufactured by a mirror lathe, and the manufacturing cost can be greatly reduced. It is done.

Embodiment 2. FIG.
In the first embodiment, the projection optical system 17 is configured by the refractive optical lens 15 having barrel distortion and the convex mirror 16 having pincushion distortion, but in the second embodiment, similarly to the convex mirror. The case where the projection optical system is configured by a Fresnel mirror that can enlarge an image at a short projection distance and has no distortion will be described.

  FIG. 5 is a diagram showing a configuration of an image display apparatus according to Embodiment 2 of the present invention. In FIG. 5, reference numeral 23 denotes a non-aberration refractive optical lens (refractive optical part), 24 denotes a Fresnel mirror (reflective part) that reflects light from the refractive optical lens 23 and projects it onto the screen 18, and 25 denotes the refractive optical lens 23. This is a projection optical system (projection optical means) composed of the Fresnel mirror 24. Similar to the convex mirror 16, the reflecting surface of the Fresnel mirror 24 has negative power. Here, the illustration of the illumination light source system is omitted.

  FIG. 6 is an enlarged view of the Fresnel mirror 24. FIG. 6 also shows the convex mirror 16 shown in the first embodiment. As the correspondence between the convex mirror 16 and the Fresnel mirror 24 in FIG. 6, the Fresnel mirror 24 divides the reflective surface of the convex mirror 16 into small sections, has the same inclination as the portion corresponding to the divided position, and has a periodic structure. It has the shape of a reflecting surface. As can be seen from FIG. 6, the Fresnel mirror 24 is thinner than the convex mirror 16.

  FIG. 7 is a diagram for comparing the difference in distortion between the convex mirror 16 and the Fresnel mirror 24. As described in the first embodiment, the optical path (broken line in FIG. 7) obtained by reflecting the lattice-like image (FIGS. 7a and 7b) in the micromirror device 14 and the non-aberration refracting optical lens 23 with the convex mirror 16 is convex. Due to the difference in reflection position of each optical path due to the above, pincushion distortion (FIG. 7c, ◯) occurs on the AA ′ cross section perpendicular to the optical axis 27 of the refractive optical lens 23. On the other hand, when the Fresnel mirror 24 is used, since the reflection positions in the optical axis direction are all the same, no distortion occurs as in the case of the plane mirror 21 in FIG. 3 (FIG. 7d, ●). Therefore, by constructing the projection optical system 25 using the Fresnel mirror 24, it is not necessary to consider the correction of distortion, and the non-aberration refractive optical lens 23 may be used as it is. Since other configurations and operations are the same as those in the first embodiment, description thereof is omitted.

  As described above, according to the second embodiment, similarly to the convex mirror, the image is enlarged at a short distance, and the Fresnel mirror 24 and the aberration-free refractive optical lens 23 that do not distort the transmitted light image are used. Since the projection optical system 25 is configured, the image can be enlarged and displayed on the screen 18 without correcting the pincushion distortion of the convex mirror 16 of the first embodiment by the refractive optical lens. An effect is obtained that the design and manufacture of the image display device can be facilitated.

  Further, according to the second embodiment, since the Fresnel mirror 24 configured to be thinner than the convex mirror 16 is used for the projection optical system 25, an image display apparatus further reduced in thickness compared with the first embodiment is provided. The effect that it can comprise is acquired.

Embodiment 3 FIG.
In the third embodiment, a case will be described in which a projection optical system is configured from an optical element and a refractive optical lens in which the surface opposite to the light incident surface is a convex reflecting surface.

  FIG. 8 is a diagram showing a configuration of an image display apparatus according to Embodiment 3 of the present invention. In FIG. 8, 28 is a refractive optical lens (refractive optical part), 29 is an optical element (reflecting part) composed of two optical materials having different dispersion characteristics, and 30 is composed of a refractive optical lens 28 and an optical element 29. A projection optical system (projection optical means). Here, the illustration of the illumination light source system is omitted.

  FIG. 9 is an enlarged view of the optical element 29. 31 and 33 are low dispersion glass (low dispersion medium) and high dispersion glass (high dispersion medium), 32 is a boundary surface between the low dispersion glass 31 and the high dispersion glass 33, and 34 is a boundary between the high dispersion glass 33 and air. It is a reflection surface. When viewed from the light incident side, the boundary surface 32 is formed in a concave shape so as to have a positive power, and the reflection surface 34 is formed in a convex shape so as to have a negative power. Similar to the principle of the prism, since chromatic aberration occurs when light enters and exits the optical element 29, the achromaticity is performed by combining the low dispersion glass 31 and the high dispersion glass 33.

Next, the operation will be described.
FIG. 10 is a diagram showing an incident optical path inside the optical element 29. In FIG. 10, the left side of the boundary surface 32 corresponds to the low dispersion glass 31 (refractive index n ₁ ), and the right side corresponds to the high dispersion glass 33 (refractive index n ₂ ). n ₁ and n ₂ can be arbitrarily selected, but here, n ₁ <n ₂ . In addition, a convex mirror having the same shape as the reflecting surface 34 is prepared, and an optical path in which incident light is simply bent using the convex mirror as the reflecting surface 34 is indicated by a broken line.

  As can be seen by comparing the solid line and the broken line, the optical system is configured such that the low-dispersion glass 31 and the high-dispersion glass 33 are sequentially transmitted through the light path when bent by a simple convex mirror and incident on the convex reflecting surface 34. The optical path by the element 29 can be bent at a larger angle, and a wider-angle image can be projected on the screen 18.

  If this optical element 29 is used, the convex surface shape of the reflective surface 34 can be made moderate as much as the image can be projected at a wider angle than the convex mirror 16 of the first embodiment. Distortion can be reduced. In addition, since the light emission position can be controlled by adjusting the thickness of the optical material of the low dispersion glass 31 or the high dispersion glass 33, the distortion generated in the reflection surface 34 is corrected inside the optical element 29. be able to.

  Next, the principle of the achromatic principle of the optical element 29 will be described. FIG. 11 is a diagram in which the optical path in the optical element 29 folded back by the reflecting surface 34 is developed in one direction. In FIG. 11, the red and blue optical paths are indicated by solid lines and broken lines, respectively. The case where the refractive index change with respect to the wavelength difference is large is called high dispersion, and the case where the refractive index change is small is called low dispersion. In general, a glass material has a characteristic that its refractive index increases as the wavelength becomes shorter.

  Therefore, as shown in FIG. 11, in the light refracted by the low dispersion glass 31, the short wavelength blue is greatly refracted, and the long wavelength red is not refracted as much as the blue. Since the degree of refraction by color is different from that of the low dispersion glass 31 in the high dispersion glass 33, even a glass having a lower power than the low dispersion glass 31 is provided with dispersion that can correct chromatic aberration generated in the low dispersion glass 31. Therefore, a positive power achromatic lens can be configured by this combination. When a negative power achromatic lens is required, the combination of the low dispersion glass 31 and the high dispersion glass 33 may be reversed.

  In FIG. 9, the low dispersion glass 31 is disposed on the light incident side. However, as shown in FIG. 12, the high dispersion glass 36 is used on the light incident side, and then the low dispersion glass 38 and the negative power are applied. In some cases, the optical element 35 using the configuration of the reflecting surface 39 having a higher achromatic effect can be obtained. These can be freely selected at the time of design.

  As described above, according to the third embodiment, the low-dispersion glass 31 and the high-dispersion glass 33 are laminated in the light transmitting direction and have negative power. Since light is projected onto the screen 18 using the optical element 29 on which the reflection surface 34 that reflects the light transmitted through the dispersion glass 33 is formed, light having a wide angle equivalent to that of the convex mirror 16 of the first embodiment is used. In addition to being able to project with a more gentle convex surface shape, it is possible to correct distortion occurring in the reflecting surface 34 by adjusting the thickness of the low dispersion glass 31 and the high dispersion glass 33 inside the optical elements 29 and 35. Thus, the effect of facilitating correction of the pincushion distortion generated on the reflecting surface 34 can be obtained.

Embodiment 4 FIG.
In the fourth embodiment, correction of distortion by a refractive optical lens using a non-spherical shape as a refractive surface or a reflective surface, or a convex mirror will be described.

  FIG. 13 is a diagram showing a configuration of an image display apparatus according to Embodiment 4 of the present invention. In FIG. 13, reference numeral 40 denotes a refractive optical lens (projection optical means, refractive optical part) having positive power, 41 denotes an aspherical convex mirror (projection optical means, reflection part) having an aspherical reflecting surface, and 42 denotes an aspherical surface. An aspherical lens (projection optical means, refractive optical part) having a refractive surface having a shape, 43 is a spherical convex mirror (projection optical means, reflecting part) having a spherical reflective surface, 44 is a refractive optical lens 40, and an aspherical convex mirror 41. The optical axis shared by the aspherical lens 42 and the spherical convex mirror 43. The illumination light source system and the screen are not shown.

  When the Fermat principle is used for analysis, no aberration can be obtained when the refractive surface of the lens or the reflective surface of the mirror is made spherical, whereas the refractive surface of the lens or the reflective surface of the mirror is aspherical. It is known that aberrations can be reduced. In the fourth embodiment, the distortion is corrected by applying an optical element having this aspherical shape to the place where the chief rays are scattered.

For example, as shown in FIG. 13A, the light from the micromirror device 14 as the light spatial modulation element is reflected by the aspherical convex mirror 41 via the refractive optical lens 40, and the light is projected onto the screen 18 (not shown). is doing.
Further, as shown in FIG. 13B, an aspherical lens 42 is installed at a place where the principal ray is scattered between the refractive optical lens 40 and the spherical convex mirror 43, and the light from the micromirror device 14 is refracted optically. The light is reflected by the spherical convex mirror 43 through the lens 40 and the aspheric lens 42, and the light is projected onto the screen 18.
Since the reflecting surface shape of the aspherical convex mirror 41 and the refracting surface shape of the aspherical lens 42 correspond to the distortion aberration on a one-to-one basis, the shape is designed by optical path tracking so as to reduce the distortion aberration in any case. .

  Accordingly, in both cases of FIGS. 13A and 13B, the light is projected onto the screen 18 through the aspherical convex mirror 41 and the aspherical lens 42 having an aspherical shape. Can be made thin, and distortion of the image projected onto the screen 18 can be corrected.

Further, as shown in FIG. 13C, both an aspheric lens 42 and an aspheric convex mirror 41 may be provided. By doing in this way, it becomes possible to correct distortion more easily.
Further, although not shown, the aspherical lens 42 is not limited to one, and a plurality of aspherical lenses 42 are provided between the refractive optical lens 40 and the aspherical convex mirror 41 (or the spherical convex mirror 43). The distortion aberration may be further corrected.

  In order to make the correction of the distortion aberration due to the aspherical shape described above more effective, the following three methods are conceivable.

  FIG. 14 is a diagram showing a configuration of an image display apparatus according to Embodiment 4 of the present invention. The illustration of the illumination light source system and the screen is omitted. In FIG. 14, reference numeral 45 denotes an aspherical convex mirror (projection optical means, reflector) having a reflective surface having a large convex curvature at the center of the optical axis 44 and having a smaller curvature toward the periphery. For comparison, the spherical convex mirror 43 (dotted line) and the light ray reflected by the spherical convex mirror 43 (dotted arrow) are shown.

  As described in the first embodiment, the spherical convex mirror 43 causes pincushion distortion and causes image distortion. Since this pincushion type distortion aberration occurs in the peripheral shape of the spherical convex mirror 43, a spherical surface mirror 45 having a large convex curvature at the center of the optical axis 44 and having a small curvature toward the periphery is used. The peripheral shape of the convex mirror 43 is corrected. As a result, distortion can be further reduced.

  FIG. 15 is a diagram showing a configuration of an image display apparatus according to Embodiment 4 of the present invention. The illustration of the illumination light source system and the screen is omitted. In FIG. 15, reference numeral 46 denotes an aspherical convex mirror (projection optical means, reflecting part) having an odd-order aspherical surface as a reflecting surface.

  In general, a three-dimensional curved surface is represented by a polynomial composed of even-order terms. An odd-order aspherical surface of the aspherical convex mirror 46 in FIG. 15 is formed by adding odd-order terms to this polynomial and setting each aspheric coefficient to an appropriate value. Compared with the aspherical surface (dotted line) of the aspherical convex mirror 45 in FIG. 14, the odd-order aspherical surface of the aspherical convex mirror 46 has a convex protrusion (or concave depression) in the vicinity of the optical axis 44. This can be seen from FIG.

  The convex protrusion (or concave depression) in the vicinity of the optical axis 44 is formed by adding odd-order terms, and the micromirror device 14 is placed outside the optical axis 44 as shown in FIG. In the case of the eccentric arrangement, light is not projected by the reflecting surface near the optical axis 44. Therefore, there is no problem in display performance even if the projection imaging performance near the optical axis is deteriorated due to the curvature discontinuity of the central portion of the aspherical convex mirror 46. By using the aspherical convex mirror 46, it is possible to realize a projection optical system that achieves both correction of distortion and good imaging characteristics of off-axis projection light.

In principle, the central part of the odd-order aspherical mirror and aspherical lens including the first-order odd-order term has a discontinuity of the curvature, and thus the reflected light / refracted light is disturbed, and the imaging performance deteriorates.
Therefore, in the fourth embodiment, the odd-numbered aspherical surface (a point on the optical axis) is reflected / transmitted to guide the projected light beam (optical image signal) onto the screen 18 so as to be favorable. The imaging performance is realized. For this reason, the micromirror device 14 is eccentrically arranged by shifting the effective display surface outside the optical axis.

Odd-order aspheric surfaces can also be applied to refractive optical lenses.
FIG. 16 is a diagram showing a configuration of an image display apparatus according to Embodiment 4 of the present invention. In FIG. 16, reference numeral 47 denotes an aspheric lens (projection optical means, refractive optical unit) in which the refractive surface facing the aspherical convex mirror 45 is formed as an odd-order aspheric surface.

  In particular, since the principal ray is more scattered at the exit portion of the refractive surface closer to the aspherical convex mirror 45 of the refractive optical lens, the shape of the exit portion is locally changed to control the shape so as to reduce distortion. Can do.

  As described above, according to the fourth embodiment, since the aspherical convex mirror 41 having the aspherical reflecting surface is provided, it is possible to correct the distortion aberration of the light projected onto the screen 18. Is obtained.

  According to the fourth embodiment, the aspherical lens 42 having at least one aspherical refracting surface is provided at the place where the principal ray is scattered between the refractive optical lens 40 and the convex mirror. The effect that the distortion of light projected onto the screen 18 can be corrected is obtained.

  Furthermore, according to the fourth embodiment, since the aspherical convex mirror 45 having a large convex curvature at the center of the optical axis and having a small curvature toward the periphery is provided, the distortion aberration of the light projected onto the screen 18 The effect that it can correct | amend more is acquired.

  Furthermore, according to the fourth embodiment, the aspherical convex mirror 46 having an odd-order aspheric surface formed by adding an odd-order term to an even-order polynomial representing an even-order aspheric surface as a reflecting surface is provided. Therefore, it is possible to realize a projection optical system that can achieve both correction of distortion and good imaging characteristics of off-axis projection light.

  Further, according to the fourth embodiment, the aspherical lens 47 having an odd-order aspheric surface formed by adding an odd-order term to an even-order polynomial representing an even-order aspheric surface as a refractive surface is provided. Therefore, the shape of the refracting surface can be locally changed, distortion can be easily reduced, and further off-axis imaging performance can be improved.

  Each shape applied to the refractive optical lens and the convex mirror can be arbitrarily selected when designing the image display device, and an appropriate combination may be selected.

  Further, a part of the refractive optical part such as the refractive optical lens 40, the aspherical lens 42, and the aspherical lens 47, that is, at least one refractive optical lens constituting the refractive optical part is represented by, for example, polycarbonate, acrylic or the like. The plastic synthetic resin can be mass-produced from a desired aspherical mold by injection molding. In general, the melting point of glass used as a lens material is about 700 ° C., and the melting point of molding glass is 500 ° C., whereas plastic synthetic resin has a lower melting point than these materials. In this case, productivity can be improved and the cost of the image display device can be reduced.

  Of course, it is also possible to manufacture the aspheric lenses 42 and 47 by molding them by a known glass mold method. In this case, since the aspherical lens is made of a glass material, the environmental characteristics (operating temperature range, humidity range, etc.) can be improved as compared with the case of manufacturing with a plastic material. The selection of the lens material for the refractive optical section may be determined according to the purpose, application, and specifications of the image display device by taking advantage of the advantages of each material.

Embodiment 5 FIG.
As shown in the fourth embodiment, distortion is corrected using an aspherical convex mirror having an aspherical reflecting surface or a refractive optical lens having an aspherical refracting surface. In the image projected onto the image 18, curvature of field occurs, and a so-called defocus phenomenon occurs. In the fifth embodiment, a method for reducing the curvature of field will be described.

  In general, the Petzval sum P is often used in considering the magnitude of the field curvature, which is expressed by the following equation (1).

P = ΣPi
= Σ [1 / (ni · fi)]
= Σ [φi / ni] (i = 1,..., N) (1)

  In Equation (1), Σ is an operator that means the summation regarding the sum index i, i is the number of the optical element, and N is the total number of optical elements. Pi represents the Petzval sum contributing component of the i-th optical element, ni represents the refractive index of the i-th optical element, fi represents the focal length of the i-th optical element, and φi represents the power of the i-th optical element.

  A condition for obtaining a planar image having no field curvature with respect to a planar object is called a Petzval condition, and the Petzval condition is satisfied when P = 0. That is, in the image display device, an image with reduced curvature of field can be displayed on the screen 18 by bringing the Petzval sum close to zero.

  As shown in FIG. 17, a case where a refractive optical lens (projection optical means, refractive optical unit, Petzval sum compensating lens) 48 is applied to, for example, FIG. 13A is considered. The refractive optical lens 48 is an achromatic lens composed of a positive lens 48A and a negative lens 48B.

  Considering the aspherical convex mirror 41 (i = 3), since the refractive index n3 = −1 and the negative power φ3 (<0) having a large absolute value, the Petzval sum is obtained by dividing the negative values. The Petzval sum contribution component P3 of the aspherical convex mirror 41 that contributes to P tends to be a positive value.

  Accordingly, the curvature of field is corrected by designing the refractive optical lens 48 that cancels the contribution component P3 of the aspherical convex mirror 41. That is, the component P1 + P2 that contributes to the Petzval sum is obtained by the refractive optical lens 48 including the positive lens 48A (i = 1) having positive power and the negative lens 48B (i = 2) having negative power. A negative value is set so as to cancel out the component P3 of the aspherical convex mirror 41.

First, since the positive lens 48A has positive power φ1 (> 0), increasing the refractive index n1 of the positive lens 48A brings the contribution component P1 = φ1 / n1≈0 and reduces the influence on the Petzval sum P. To do.
Since the negative lens 48B has negative power φ2 (<0), the negative lens 48B has a large absolute value and a negative contribution component P2 = φ2 / n2 by reducing the refractive index n2 of the negative lens 48B. To.
As described above, by making the refractive indexes of the positive lens 48A and the negative lens 48B satisfy n1> n2, P1 + P2 can be as close to a negative value as possible, and the influence of P1 + P2 on P3 can be reduced. Become.

  Furthermore, the Petzval condition can be further satisfied by setting the Abbe number ν1 of the positive lens 48A and the Abbe number ν2 of the negative lens 48B to a close value. In general, when a refractive index change due to a wavelength change is Δn, it is defined by an Abbe number ν = (n−1) / Δn (n is a refractive index), and when the Abbe number is small, it means an optical material having a high dispersion value. .

  Assuming that the combined power of the positive lens 48A and the negative lens 48B of the refractive optical lens 48 in FIG. 17 is Φ, the combined power expression Φ = Σ (φi) and the achromatic condition expression Σ (φi / νi) = 0. (2) and (3) are obtained.

φ1 = Φ · ν1 / (ν1−ν2) (2)
φ2 = −Φ · ν2 / (ν1−ν2) (3)

  Equations (2) and (3) are transformed into equations (4) and (5), respectively, to show how the absolute values of (φ1 / Φ) and (φ2 / Φ) change with respect to (ν2 / ν1). As shown in FIG.

φ1 / Φ = 1 / [1- (ν2 / ν1)] (4)
φ2 / Φ = − (ν2 / ν1) / [1- (ν2 / ν1)] (5)

  In FIG. 18, the horizontal axis represents (ν2 / ν1), and the vertical axis represents the absolute values of equations (4) and (5), | φ1 / Φ |, | φ2 / Φ |. As can be seen from FIG. 18, the powers φ1 and φ2 of the positive lens 48A and the negative lens 48B increase as (ν2 / ν1) approaches 1, that is, the values of ν1 and ν2 become closer.

  By utilizing this fact, the power of the positive lens 48A and the negative lens 48B constituting the refractive optical lens 48 can be increased to further satisfy the Petzval condition. That is, the refractive index n1 of the positive lens 48A is increased, the refractive index n2 of the negative lens 48B is decreased, and the Abbe number ν1 of the positive lens 48A and the Abbe number ν2 of the negative lens 48B are set to be close values. .

  For example, the refractive indexes of the positive lens 48A and the negative lens 48B are n1 = n2 = 1.6, respectively, and the Abbe numbers of the positive lens 48A and the negative lens 48B are ν1 = 50 and ν2 = 30, respectively. Assuming that the combined power Φ = 1 in 3), φ1 = 50 / (50-30) = 2.5 and φ2 = −30 / (50-30) = − 1.5. The Petzval sum of the lens 48 is P1 + P2 = (2.5 / 1.6) + (− 1.5 / 1.6) = 0.625.

  From this state, the refractive index of the positive lens 48A is increased and the refractive index of the negative lens 48B is decreased so as to approach the Petzval condition. For example, if the refractive index of the positive lens 48A is larger than that of the negative lens 48B with n1 = 1.8 and n2 = 1.6, the Petzval sum P1 + P2 = (2.5 / 1.8) + (− 1.5 / 1.6) ) = 0.4514, approaching a negative value before the refractive indexes n1 and n2 are changed, and the Petzval sum P is improved.

  Subsequently, the Abbe numbers ν1 and ν2 of the positive lens 48A and the negative lens 48B are set to close values. For example, when the Abbe number difference ν1−ν2 is reduced as in ν1 = 45 and ν2 = 43, φ1 = 45 / (45−43) = 22.5, φ2 = −43 from the equations (2) and (3). /(45−43)=−21.5 (assuming Φ = 1), Petzval sum P1 + P2 = (22.5 / 1.8) + (− 21.5 / 1.6) = − 0. 9375, and the Petzval sum P1 + P2 of the refractive optical lens 48 can be set to a negative value. Accordingly, the Petzval sum P in FIG. 17 including the aspherical convex mirror 41 can be brought close to 0, and the curvature of field can be reduced.

  As described above, according to the fifth embodiment, the positive lens 48A having positive power and the negative lens 48B having negative power are configured, and the refractive index of the positive lens 48A is set to be higher than the refractive index of the negative lens 48B. And a refractive optical lens 48 in which the Abbe number of the positive lens 48A and the Abbe number of the negative lens 48B are set to close values are provided, so that distortion aberration is compensated and the Petzval condition is satisfied. It becomes possible to compensate for the surface curvature, and the effect that the imaging performance can be improved is obtained.

  In the above description, the refractive optical lens 48 of FIG. 17 is used in FIG. 13A. However, the fifth embodiment is not limited to this, and other configurations shown in the fourth embodiment are used. It is also possible to apply to.

Embodiment 6 FIG.
In the sixth embodiment, a method of generating an excessive curvature of field with a refractive optical lens in order to compensate for curvature of field generated with an aspherical convex mirror will be described.

  FIG. 19 is a diagram for explaining the under field curvature that occurs in an aspherical convex mirror. In FIG. 19A, 49 is a refractive optical lens, 50 is an optical axis of the refractive optical lens 49, and 51 is a plane perpendicular to the optical axis 50. The light transmitted through the refractive optical lens 49 forms an image on the flat surface 51, and a flat image is obtained in FIG.

When light is projected onto the aspherical convex mirror of the fourth embodiment through the refractive optical lens 49, the best image plane is a curved surface with the concave surface facing the projection optical system side due to the under field curvature generated by the aspherical convex mirror. Become.
For example, as shown in FIG. 19B, when light is emitted from the refractive optical lens 49 to the aspherical convex mirror 41, the reflected light exhibits field curvature like the image plane 52, and the out-of-focus image is displayed on the screen. 18 is displayed. In order to correct the under curvature of field of the aspherical convex mirror 41, an excessive curvature of field is generated in the refractive optical system so that the projected image plane is flattened.

  That is, as shown in FIG. 20, a refractive optical system in which an image surface 53 having an over curvature of field whose distance to the focal point becomes farther away from the optical axis 44 is provided between the micromirror device 14 and the aspherical convex mirror 41. It is generated by the lens (projection optical means, refractive optical unit, field curvature compensation lens) 54, and cancels the over field curvature of the refractive optical lens 54 and the under field curvature of the aspherical convex mirror 41. By doing so, it becomes possible to correct the under curvature of field of the aspherical convex mirror 41 used for correcting the distortion, and an image having no distortion and no curvature of field can be obtained. Can be displayed.

  As the shape of the refractive surface of the refractive optical lens 54, an optimal refractive surface shape can be determined by numerical calculation of optical path tracking using a computer.

  In addition, by applying an aspherical optical element to the main rays where the chief rays are scattered or where the chief rays are gathered, distortion is caused at the chief rays where the chief rays are scattered, and curvature of field is obtained at the chief rays where they are gathered. It is known from the result of numerical calculation of optical path tracking that it can be effectively reduced. An example of this is shown in FIG.

  FIG. 21 is a diagram showing the numerical calculation results of optical path tracking. An aspherical lens (projection optical means, refractive optical unit, aspherical optical element) 55 is provided at a place where light from a micromirror device 14 (not shown) is gathered. Aspherical lenses (projection optical means, refracting optical unit, aspherical optical element) 56A and 56B are disposed at the positions where the light from the aspherical lens 55 is scattered, and aspherical surfaces are disposed at the positions where the light from the aspherical lens 56B is scattered. A convex mirror (projection optical means, reflecting portion, aspherical optical element) 57 is provided, and the light reflected by the aspherical convex mirror 57 is projected onto a screen 18 (not shown). The aspherical lens 55 can effectively reduce field curvature, and the aspherical lenses 56A and 56B and the aspherical convex mirror 57 can effectively reduce distortion.

<Numerical Example 6A>
An example of the numerical calculation result of FIG. 21 is shown in FIG. The definition formula of the aspherical shape used in FIG. 22 is as the formulas (6) and (7). Where z is the amount of sag from the tangential plane passing through the center of rotation of the optical surface, c is the curvature at the surface vertex (the reciprocal of the radius of curvature), k is the conic coefficient, and r is the distance from the z-axis. The specifications in FIG. 22 are f = 5.57 mm (focal length at a wavelength of 546.1 nm), NA = 0.17 (micromirror device side numerical aperture), and Yob = 14.22 mm (micromirror device side object). High), M = 86.3 × (projection magnification).

z = cr ² / [1+ {1- (1 + k) c ² r ² } ^0.5 ]
+ Ar ⁴ + Br ⁶ + Cr ⁸ + Dr ¹⁰ + Er ¹²
+ Fr ¹⁴ + Gr ¹⁶ + Hr ¹⁸ + Jr ²⁰ (6)
z = cr ² / [1+ {1- (1 + k) c ² r ² } ^0.5 ]
+ AR1r + AR2r ² + AR3r ³ + ...
+ ARnr ⁿ + ... + AR30r ³⁰ (7)

  As described above, according to the sixth embodiment, since the refracting optical lens 54 generates an excessive field curvature that cancels the under field curvature of the aspherical convex mirror 41, the distortion aberration is corrected. At the same time, it is possible to display an image with corrected curvature of field.

  Further, according to the sixth embodiment, since the aspherical optical surface is applied to the place where the chief rays are scattered and where the chief rays are gathered, the curvature of field is caused at the place where the chief rays are gathered. The effect that distortion can be effectively reduced where the chief rays are scattered is obtained.

  The refractive optical lens 54 may be applied to the other aspherical convex mirror shown in the fourth embodiment, and the same effect can be obtained.

Embodiment 7 FIG.
FIG. 23 is a diagram showing a configuration of an image display apparatus according to Embodiment 7 of the present invention. FIGS. 23A, 23B, and 23C are a front view, a top view, and a side view of the image display device, respectively. In FIG. 23, reference numeral 58 denotes a refractive optical lens (projection optical means, refractive optical unit) that mediates light from the micromirror device 14, and corresponds to the refractive optical lens described in each embodiment. Reference numeral 59 denotes an optical path bending reflecting mirror (optical path bending means) that reflects light from the refractive optical lens 58, and reference numeral 60 denotes a convex mirror (projection optical means, reflecting portion) having a negative power, which has been described in each embodiment. It is a convex mirror. Reference numeral 61 denotes an optical axis of the convex mirror 60. In FIG. 23, the illumination light source system is not shown.

  The refractive optical lens 58 and the convex mirror 60 of FIG. 23 are manufactured with a common optical axis, and in order to obtain the arrangement configuration of FIG. Is bent at an appropriate angle within a horizontal plane including the optical axis 61 of the convex mirror 60. In other words, from the state in which the optical axes of the refractive optical lens 58 and the convex mirror 60 coincide with each other, the optical axis of the refractive optical lens 58 is rotated around the normal line of the horizontal plane including the optical axis 61 of the convex mirror 60 until an appropriate orientation is obtained. ing. In this way, the refractive optical lens 58 is arranged in the empty space of the image display device.

  In FIG. 23, the light from the micromirror device 14 transmitted through the refractive optical lens 58 is first reflected to the convex mirror 60 side by the optical path bending reflector 59, and the light reflected by the convex mirror 60 is described in the first embodiment. The light is reflected by the plane mirror 22 and projected onto the screen 18 at a wide angle. In particular, by arranging the reflecting surface of the plane mirror 22 and the light receiving surface (or image display surface) of the screen 18 in parallel, the thinnest image display device can be configured. The point in the seventh embodiment is that the light from the refractive optical lens 58 disposed in the empty space of the image display device is reflected to the convex mirror 60 by the optical path bending reflecting mirror 59. Since the refractive optical lens 58 and an illumination light source system (not shown) can be disposed in the empty space, the thickness of the image display device can be reduced.

The effect of this optical path bending reflector 59 can be understood by comparing FIG. 23 with FIGS.
That is, in FIG. 24, since the optical path bending reflector 59 is not provided, the light transmitted through the refractive optical lens 58 is directly emitted to the convex mirror 60, and the micromirror is positioned at a position determined from the screen 18, the plane mirror 22, and the convex mirror 60. The device 14, the refractive optical lens 58, and the like need to be disposed, so that the device is configured thicker than the image display device of FIG.

  In FIG. 25, although the optical path bending reflector 59 is provided, the optical axis direction of the refractive optical lens 58 is bent in a plane other than the horizontal plane including the optical axis of the convex mirror 60 (in the vertical plane in FIG. 25). Therefore, the refractive optical lens 58, the micromirror device 14, the illumination light source system (not shown), and the like are arranged below the convex mirror 60, and the lower portion of the screen is configured higher than the image display device of FIG. End up.

  Therefore, by using the optical path bending reflector 59 that reflects the light from the refractive optical lens 58 arranged in the empty space to the convex mirror 60 as shown in FIG. 23, the image display device is further thinned, and the screen lower portion height is lowered. Can be configured.

  Although not shown, an optical path bending reflector may be used for a refractive optical lens (projection optical means, refractive optical unit) composed of a plurality of lenses. In other words, an optical path bending reflector is inserted between the first lens means and the second lens means of the plurality of lenses constituting the refractive optical lens, and the two lenses are reflected by reflection by the optical path bending reflector. To mediate light. The first lens means and the second lens means are a lens group composed of at least one refractive optical lens. In this case, since it is not necessary to configure the optical axis of the first lens means and the optical axis of the second lens means coaxially, the refractive optical lens can be configured by bending the two optical axes. become. Even in this case, the image display device can be thinned as in FIG.

  When the refractive optical lens is composed of a large number of lenses, a plurality of optical path bending reflectors may be used according to the number of lenses.

  Also, an optical path bending reflecting mirror that reflects light from the refractive optical lens to the convex mirror and an optical path bending reflecting mirror that reflects light from any lens of the refractive optical lens to another lens may be used in combination. It is possible to design according to the specifications of the image display device.

  As described above, according to the seventh embodiment, the optical axis direction of the refractive optical lens 58 is bent at an appropriate angle in the horizontal plane including the optical axis 61 of the convex mirror 60, and the light emitted from the refractive optical lens 58 is reflected. Since the optical path bending reflecting mirror 59 that reflects to the convex mirror 60 is provided, the refractive optical lens 58 and the illumination light source system can be arranged in the empty space of the image display device, and the screen is further reduced in thickness. The effect that the image display apparatus which restrained height low can be comprised is acquired.

  Further, according to the seventh embodiment, since the optical path bending reflector for reflecting the light from the first lens means constituting the refractive optical lens to the second lens means is provided, the first lens is provided. The refractive optical lens can be formed by bending the optical axis of the means and the optical axis of the second lens means, and the lens is arranged by utilizing an empty space to further reduce the thickness and reduce the height of the lower portion of the screen. The effect that the image display apparatus which restrained this low can be comprised is acquired.

  The seventh embodiment can be applied to the first to sixth embodiments.

Embodiment 8 FIG.
As described in Numerical Example 6A of Embodiment 6, the optimum configuration of the optical system for achieving the object of the present invention can be specifically obtained by numerical calculation of ray tracing using a computer. In the eighth embodiment, the result of the numerical calculation will be disclosed.

  FIG. 26 is a diagram showing a configuration of an image display apparatus according to Embodiment 8 of the present invention, and Numerical Example 6A (FIG. 21) is used. Reference numeral 14 which is the same as in FIG. 1 is a micromirror device. In FIG. 26, reference numeral 62 denotes a retro optical system (projection optical means, refractive optical unit) composed of a positive lens group having a positive power and a negative lens group having a negative power, and 63 finely adjusts the light emission angle. A refractive optical lens (projection optical unit, refractive optical unit) 64 is an aspherical convex mirror (projection optical unit, reflective unit) that reflects light from the refractive optical lens and corrects distortion. The illumination light source unit and the screen are not shown.

  Light from a micromirror device (not shown) passes through the retro optical system 62, is emitted to the convex mirror 64 via the refractive optical lens 63, and is projected onto a screen (not shown). At this time, the retro optical system 62 has a condensing function and assists in expanding the angle of view of the light beam projected onto the screen. The refractive optical lens 63 has a function of correcting distortion that cannot be corrected by the aspherical convex mirror 64. The retro optical system 62 and the refractive optical lens 63 include the various refractive optical lenses described in the embodiments.

  More specifically, from the two positive lens groups 62A and 62B and one negative lens group 62C in FIG. 27A, the two positive lens groups 62D and 62E and one negative lens group 62F in FIG. The retro optical system 62 is composed of one positive lens group 62G and one negative lens group 62H in FIG.

  The above configuration is a configuration derived by numerical calculation in order to achieve the object of the present invention, and the effect that distortion and field curvature can be suppressed and a thin image display device can be configured is implemented by each numerical value. It can be easily understood by performing the numerical calculation again using the numerical calculation result shown in the example. Specific numerical calculation results are shown as Numerical Examples 8A, 8B, and 8C, respectively.

<Numerical Example 8A>
28 and 29 are diagrams respectively showing numerical data and configuration of numerical example 8A, and correspond to FIG. 27 (a). The positive lens group 62B is an achromatic lens composed of a positive lens and a negative lens.

<Numerical Example 8B>
30 and 31 are diagrams respectively showing numerical data and configuration of Numerical Example 8B, and correspond to FIG. 27B. Here, the positive lens group 62E is composed of one lens.

<Numerical Example 8C>
32 and 33 are diagrams respectively showing numerical data and configuration of numerical example 8C, and correspond to FIG. 27C.

  Further, FIGS. 34 to 37 disclose numerical examples 4A and 4B relating to the fourth embodiment, and FIGS. 38 and 39 disclose numerical examples 7A relating to the seventh embodiment, respectively.

<Numerical Examples 4A and 4B>
34 and 35 are diagrams showing numerical data and configuration of Numerical Example 4A, respectively. FIGS. 36 and 37 are diagrams showing numerical data and configuration of Numerical Example 4B, respectively. Both correspond to the fourth embodiment. Of the two aspherical lenses 47, the one closer to the aspherical convex mirror 46 is made of acrylic and the farther one is made of polycarbonate.

  In general, the refractive index temperature coefficient and the linear expansion coefficient temperature coefficient of plastic are about two orders of magnitude larger than those of glass. Therefore, special consideration is required regarding the method of use when the plastic is used in an environment with a large temperature change. Therefore, particularly in Numerical Example 4B, the thickness of the central portion and the thickness of the peripheral portion are substantially equal in the shape of the two aspheric lenses 47, and the influence of the change in the shape of the aspheric lens 47 on the temperature change is affected. Environmental characteristics are improved by reducing the environmental characteristics.

<Numerical Example 7A>
38 and 39 are diagrams showing numerical data and configuration of Numerical Example 7A, respectively. This corresponds to the seventh embodiment, and corresponds to a case where an optical path bending reflecting mirror is inserted into the bending position in the figure to aim for thinning of the image display device.

  It should be noted that the specifications and formulas for calculating the aspheric shape for all the numerical examples described above are the same as in the numerical example 6A except for the value of the focal length f at a wavelength of 546.1 nm. The focal length f of each numerical example is as follows.

Numerical Example 4A: f = 5.3881 mm
Numerical Example 4B: f = 4.9898 mm
Numerical Example 7A: f = 4.8675 mm
Numerical Example 8A: f = 5.2190 mm
Numerical Example 8B: f = 5.0496 mm
Numerical Example 8C: f = 5.5768 mm

  By verifying the numerical data shown in each numerical example above, the following characteristics can be found in the lens of the retro optical system 62.

(Feature 1) The average value ave_Nn of the refractive index of the negative lens having negative power and the average value ave_Np of the refractive index of the positive lens having positive power are 1.45 ≦ ave_Nn ≦ 1.722, 1.722 <, respectively. ave_Np ≦ 1.9.
(Feature 2) The average value ave_νdn of the negative lens and the average value ave_νdp of the Abbe number of the positive lens are 25 ≦ ave_νdn ≦ 38 and 38 <ave_νdp ≦ 60, respectively.
(Characteristic 3) The difference dif_ave_N between the average value of the refractive index of the glass material constituting the positive lens and the average value of the refractive index of the glass material constituting the negative lens is 0.04 ≦ dif_ave_N ≦ 1.
(Feature 4) The difference dif_ave_νd between the average value of the Abbe number of the glass material constituting the positive lens and the average value of the Abbe number of the glass material constituting the negative lens is 0 ≦ dif_ave_νd ≦ 16.

  Features 1 and 2 correspond to increasing the refractive index of the positive lens 48A and decreasing the refractive index 48B of the negative lens in the refractive optical lens 48 (Petzval sum compensating lens) shown in the fifth embodiment. . In general, an Abbe number of 70 to 90 is used for applications such as achromatism. As can be seen from the feature 2, the Abbe number is 60 or less.

  The above is the result of the numerical example derived by numerical calculation of ray tracing using a computer.

  In the present invention, since the micromirror device is eccentrically arranged outside the common optical axis of the projection optical system and the light is incident obliquely on the optical system, a part of the light beam is effectively placed on the lens frame or the like. Care must be taken not to reduce the luminous flux. In this eighth embodiment, a configuration as shown in FIG.

  That is, in the configuration of FIG. 26, the back focal length (back focal length: English, abbreviated as BFL), which is the distance from the lens closest to the micromirror device 14 to the micromirror device 14 (transmission means light exit surface), The distance from the micromirror device 14 to the entrance pupil position of the retro optical system 62 is made to coincide. By doing so, it is possible to minimize light scattering and increase the illumination efficiency of the screen. The reason for this will be described next.

  The chief rays reflected from the small mirrors of the micromirror device 14 gather at the entrance pupil position. Since the spread angle of the reflected light from each small mirror is constant, when the entrance pupil position coincides with BFL as shown in FIG. 40 (a), the light rays are most concentrated at the position of BFL. The size (diameter) of the refractive optical lens 66 disposed in the BFL can be minimized. At this time, the refractive optical lens 65 that mediates light from an illumination light source system (not shown) to the micromirror device 14 does not emit light from the micromirror device 14 toward the refractive optical lens 66.

  On the other hand, for example, as shown in FIG. 40 (b), if the size and arrangement of the refractive optical lenses 65 and 66 and the micromirror device 14 are left as they are, the entrance pupil position is shifted from the BFL. Since the principal ray from the mirror gathers at the shifted entrance pupil position and the light spread angle is constant, the ray at the BFL position spreads compared to FIG. 40A, and the diameter of the lens that receives this light becomes larger. Further, the light incident on the refractive optical lens 66 from the micromirror device 14 is scattered by the refractive optical lens 65. This leads to a decrease in effective luminous flux and deteriorates illumination efficiency.

  For the reasons described above, the distance from the micromirror device 14 to the entrance pupil position is made equal to the BFL. This makes it possible to minimize the size (diameter) of the refractive optical lens and reduce the amount of light. It is possible to reduce this and improve the illumination efficiency. Needless to say, the technique for minimizing the distortion shown here can also be applied to other embodiments. In Numerical Embodiments 4A and 4B, the entrance pupil position is in a state substantially coincident with BFL, but the best effect can be obtained by making it coincide completely.

  As described above, according to the eighth embodiment, the retro optical system 62 including the positive lens group and the negative lens group, the refractive optical lens 63 for finely adjusting the light emission angle, and the distortion aberration are corrected. Since the aspherical convex mirror 64 is provided, an effect that distortion and field curvature are suppressed and a thin image display device can be obtained can be obtained.

  Further, according to the eighth embodiment, since the retro optical system 62 is configured by the positive lens group 62A (62D), the positive lens group 62B (62E), and the negative lens group 62C (62F), distortion aberration and The effect that the curvature of field can be suppressed and the thinned image display device can be configured more specifically is obtained.

  Further, according to the eighth embodiment, since the retro optical system 62 is configured by the positive lens group 62G and the negative lens group 62H, an image display apparatus that is reduced in thickness by suppressing distortion aberration and field curvature. The effect that it can comprise more concretely is acquired.

  Further, according to the eighth embodiment, the average refractive index value of the negative lens is in the range of 1.45 or more and 1.722 or less, and the average refractive index value of the positive lens is in the range of more than 1.722 and 1.9 or less. As a result, it is possible to obtain an effect that the distortion and the curvature of field can be suppressed and the thinned image display device can be configured more specifically.

  Further, according to the eighth embodiment, the average value of the Abbe number of the glass material constituting the negative lens is 25 or more and 38 or less, and the average value of the Abbe number of the glass material constituting the positive lens is larger than 38 and 60 or less. Therefore, it is possible to obtain an effect of suppressing the distortion aberration and the curvature of field and more specifically configuring the thinned image display device.

  Further, according to the eighth embodiment, the difference between the average value of the refractive index of the glass material constituting the positive lens and the average value of the refractive index of the glass material constituting the negative lens is 0.04 or more and 1 or less. Since the refractive optical lens is configured, it is possible to obtain an effect that the distortion and the curvature of field can be suppressed and the thinned image display device can be configured more specifically.

  Further, according to the eighth embodiment, the refractive index is changed from the lens glass material in which the difference between the average value of the Abbe number of the glass material constituting the positive lens and the average value of the Abbe number of the glass material constituting the negative lens is from 0 to 16. Since the lens is configured, it is possible to obtain an effect that the distortion and the curvature of field can be suppressed and the thinned image display device can be configured more specifically.

  Further, according to the eighth embodiment, the BFL from the refractive optical lens closest to the micromirror device 14 to the micromirror device 14 and the distance from the micromirror device 14 to the entrance pupil position of the retro optical system 62 are matched. As a result, the size (diameter) of the refractive optical lens can be minimized, and the effect that the illumination efficiency can be improved by minimizing the scattering of light can be obtained.

Embodiment 9 FIG.
In the ninth embodiment, a method of satisfying the Petzval condition by arranging a negative lens having a negative power at a low marginal ray (marginal ray) between the micromirror device and the reflecting mirror will be described. To do.

  FIG. 41 is a diagram showing the configuration of an image display apparatus according to Embodiment 9 of the present invention. FIGS. 41 (a) and 41 (b) are an overall view and an enlarged view, respectively. Illustration of an illumination light source part, a micromirror device, a screen, etc. is omitted. 41, reference numerals 67 and 68 denote refractive optical lenses, 69 denotes a convex mirror having a positive Petzval sum contribution component, 70 denotes an optical axis shared by the refractive optical lenses 67 and 68 and the convex mirror 69, and 71 denotes a micromirror device (not shown). Reference numeral 72 denotes a marginal ray of light traveling from the first to the convex mirror 69, and a negative lens having a negative power disposed at a lower position of the marginal ray 71.

  As described in the fifth embodiment, since the convex mirror 69 has a positive Petzval sum contribution component, the Petzval sum of the entire projection optical system including the refractive optical lenses 67 and 68 and the convex mirror 69 is a positive value. And curvature of field occurs. Therefore, by adding a negative lens 72 having a negative power having a large absolute value to create a negative Petzval sum contribution component and reducing the Petzval sum of the entire optical system to 0, field curvature can be reduced. Is possible.

  The point of the ninth embodiment is that when the negative lens 72 is arranged, a place where the marginal ray 71 is low is selected as a place where the negative lens 72 is arranged. That is, in the ninth embodiment, the negative lens 72 is arranged at a low position of the marginal ray 71 between the micromirror device (not shown) and the convex mirror 69. Light is concentrated around the optical axis 70 at a low marginal ray 71.

  By doing so, light concentrates on a minute portion around the center of the negative lens 72, so that the lens effect of the negative lens 72 on the light can be almost ignored. Therefore, it is not necessary to consider the influence of the negative lens 72 on the optical path design based on the refractive optical lenses 67 and 68 and the convex mirror 69, and the positive Petzval sum contribution component of the projection optical system is canceled out. be able to. It is not necessary to consider the influence on the optical path, and only the absolute value of the negative power and the refractive index of the glass material should be considered so as to satisfy the Petzval condition, so that the field curvature can be easily reduced.

More specifically, the retro optical system 62 according to the eighth embodiment may be provided with a negative lens 72, or a reflective surface of a micromirror device (in the case of a transmissive light spatial modulation element such as a liquid crystal). Is equivalent to a lower portion of the marginal ray 71, a condenser lens (field flattener) may be provided as a negative lens 72 close to the reflecting surface (outgoing surface).
The configuration of the negative lens 72 is not particularly limited to one lens, and it is possible to include a negative lens 72 composed of a plurality of lenses.

  As described above, according to the ninth embodiment, since the negative lens 72 having a negative power is arranged at a low position of the marginal ray 71, the lens effect on the transmitted light of the negative lens 72 is taken into consideration. Therefore, a negative Petzval sum contribution component that cancels out the positive Petzval sum contribution component of the projection optical system can be created to satisfy the Petzval condition easily, and an image display device with reduced field curvature can be configured. The effect of being able to be obtained.

Embodiment 10 FIG.
In the seventh embodiment, in order to minimize both the thickness of the image display device and the height of the lower part of the screen, an optical path bending reflecting mirror 59 is inserted between the refractive optical lens 58 and the convex mirror 60, and the optical axis 61. The optical path was bent in a horizontal plane including In the tenth embodiment, the relative arrangement conditions of the optical path bending reflecting mirror 59 and the refractive optical lens 58 shown in the seventh embodiment with respect to the convex mirror 60 will be described.

  42A and 42B are diagrams for explaining the arrangement conditions of the optical path bending reflector. FIGS. 42A and 42B are a side view and a top view, respectively, and FIG. 42C is a front view of the convex mirror 60. . The same or corresponding components as those in FIG. 23 are denoted by the same reference numerals. 42, reference numeral 73 denotes an optical axis of the refractive optical lens 58, and 58z denotes a refractive optical lens 58 when the optical path bending reflector 59 is virtually removed and the optical axis 61 and the optical axis 73 of the convex mirror 60 are made to coincide. is there.

  The optical axis 61 and the optical axis 73 intersect at a bending angle θ in the horizontal plane. The optical axis 73 is rotated by 180-θ degrees in the horizontal plane from the state coincident with the optical axis 61, as shown in FIG. P and Q are two points on the line of intersection between the horizontal plane including the optical axis 73 and the refractive optical lens 58, and the point P closest to the optical path from the optical path bending reflector 59 to the convex mirror 60 is provided with the plane mirror 22. Q is the point closest to the plane mirror installation surface of the image display device.

  Further, the distance from the convex mirror installation surface (reflection unit installation surface) of the image display device provided with the convex mirror 60 to the position of the optical path bending reflective mirror 59 (intersection of the optical axis 61 and the optical axis 73) is b, the optical axis The point closest to the convex mirror installation surface at the point on the intersection of the horizontal plane 61 and the optical path bending reflector 59 is called the nearest point, and the point farthest from the convex mirror installation surface is called the farthest point. The distance from the farthest point to the convex mirror installation surface is c. The distance c is the longest distance from the convex mirror installation surface to the light bending reflector 59.

  Further, the height from the highest point of the optical path bending reflector 59 to the optical axis 61 is m, the distance from the point Q to the convex mirror installation surface is g, and the distance from the exit pupil position of the refractive optical lens 58z to the convex mirror installation surface. Is defined as f. The distance g is the longest distance from the convex mirror installation surface to the refractive optical lens 58. Therefore, the total distance between the distance from the exit pupil position of the refractive optical lens 58 to the position of the optical path bending reflector 59 and the horizontal distance from the position of the optical path bending reflector 59 to the convex mirror installation surface is also f. .

  As can be seen from FIG. 42A, in order to minimize the height of the lower part of the screen, which is the distance from the lowermost end of the screen 18 to the optical axis 61, the reflected light beam 75 of the convex mirror 60 directed to the lowermost end of the screen 18 can be generated. It is advantageous to pass through a low position as close to the optical axis 61 as possible. On the other hand, when the optical path passes through an excessively low position, the optical path is bent by the optical path bending reflector 59, and a portion that cannot be displayed as a shadow on the screen is generated, which is not practical. Therefore, the size and position of the optical path bending reflector 59 must be determined so that the reflected light of the convex mirror 60 directed to the lowermost end of the screen 18 is not blocked by the optical path bending reflector 59.

  With respect to the position of the optical path bending reflector 59, the distance a is made as large as possible in order to allow the reflected light beam of the convex mirror 60 to pass through as low an optical path as possible. On the other hand, since the thickness of the image display device has a thickness limit value determined by the specification of thinning, the distance c needs to be equal to or less than the thickness limit value.

  When the optical path is bent under the above conditions, if the distance f is too short, the portion including the point P of the refractive optical lens 58 blocks the light beam from the optical path bending reflector 59 to the convex mirror 60. Alternatively, if the portion including the point P of the refractive optical lens 58 is set so as not to block the light beam from the optical path bending reflector 59 to the convex mirror 60, the distance a becomes shorter than necessary. On the other hand, if the distance f is too long, the position of the refractive optical lens 58 is more than necessary from the optical path bending reflector 59 due to the conditions of the light receiving surface of the convex mirror 60 and the optical path bending reflector 59, resulting in the optical path bending. The reflecting mirror 59 becomes large, and the height m of the optical path bending reflecting mirror 59 must be set to a large value, and the reflected light beam 75 reflected from the convex mirror 60 toward the lowermost end of the screen 18 is blocked. For this reason, an optimum value exists for the distance f.

  As can be seen from FIG. 42B, if the bending angle θ is set too large, the distance g or the distance c exceeds the thickness limit value and the distance a is short. That is, the height of the reflected light beam from the convex mirror 60 toward the lowermost end of the screen 18 is raised.

  On the contrary, if the bending angle θ is reduced, the distance g or the distance c is also reduced, so that the refractive optical lens 58 or the optical path bending reflector 59 is advantageous from the viewpoint of thickness. However, if the bending angle θ is too small, a portion including the point P of the refractive optical lens 58 enters the optical path from the optical path bending reflector 59 to the convex mirror 60 to block the light, and the shadow cannot be projected. Part will occur. Therefore, there is an optimum value for the bending angle θ.

  Based on the above, the bending angle θ of the optical path is determined so that the point P is as close as possible to the optical path from the optical path bending reflector 59 to the convex mirror 60 within a range that does not block light.

When the bending angle θ is determined, the distance g or distance c restricts the thickness of the image display device at this time. Therefore, the distance f is set so that the larger one of these distances becomes the thickness limit value. Decide. In particular, if the distance c and the distance g are set equal, the lower part of the screen can be minimized.
The bending angle θ may be determined in advance depending on other conditions of the image display device, but may be considered in the same manner as described above.

  The above results are summarized in the following 1-3. By optimizing the distance f and the bending angle θ as in 1 to 3 below, the screen lower portion height is reduced by satisfying the restriction of the thickness limit value without generating a shadow portion where the image cannot be projected. The effect that it can suppress is acquired.

  1. When the optical path is bent by the optical path bending reflector 59, the bending angle is set so that the point P of the refractive optical lens 58 is as close as possible to the optical path as long as the optical path from the optical path bending reflector 59 to the convex mirror 60 is not blocked. Set θ.

  2. When the bending angle θ is determined in advance according to other arrangement conditions of the image display device, the point P of the refractive optical lens 58 is set as much as possible within a range that does not block the optical path from the optical path bending reflector 59 to the convex mirror 60. The distance f is set so that the distance c or the distance g becomes the thickness limit value close to the optical path.

  3. In order to keep the lower part of the screen to the lowest height, the bending angle θ is set so that the point P of the refractive optical lens 58 is as close as possible to the optical path as long as the optical path from the optical path bending reflector 59 to the convex mirror 60 is not blocked. In addition, the distance f is set so that the distance c and the distance g are equal, and the distance c and the distance g are equal to the thickness limit value.

  When the point P is brought close to the optical path from the optical path bending reflector 59 to the convex mirror 60 by deleting from the refractive optical lens 58 the lens part (non-transmission part) including the point P through which the light does not pass, the optical path The refractive optical lens 58 can be brought closer to the optical path from the bending reflector 59 to the convex mirror 60 as compared with the case where the optical path is not deleted.

  Further, as can be seen from FIGS. 1 and 4, for example, light is not projected onto the screen using all the reflecting surfaces of the convex mirror, but is projected only with a reflecting surface that is half or less of the convex mirror. Therefore, for example, if a part having a non-reflective surface that does not project light onto the screen (non-reflective part) is cut out, such as the convex mirror 60 in FIG. It is possible to reduce the cost of the image display device by configuring the convex mirror to be small, and to obtain an effect that the configuration space inside the image display device can be used effectively. Further, it is possible to cut one half of the convex mirror that has been rotationally divided into two equal parts, and to apply each of the two half-divided convex mirrors to two image display devices, thereby simplifying the manufacturing process of the image display device. .

  In this invention, ray tracing is performed so as to correct distortion, and the shapes of the constituent elements of the refractive optical lens 58, the optical path bending reflector 59, and the convex mirror 61 are determined and arranged. It is necessary to form the optical path accurately while maintaining the positional relationship of the components. For this purpose, a holding mechanism 74 as shown in FIG. 43 is provided so that the refractive optical lens 58, the optical path bending reflecting mirror 59, and the convex mirror 60 are integrally held. By doing so, the mutual positional relationship can be fixed, and the optical path between the components can be manufactured with high accuracy. The stress applied from the outside of the optical system and various environmental conditions (temperature, humidity, etc.) Even if a change occurs, the relative positional relationship among the refractive optical lens 58, the reflecting mirror 59, and the convex mirror 60 is less likely to change, and the effect of further stabilizing the performance of the image display device can be obtained. Of course, when the optical path bending reflector 59 is not provided, that is, only the refractive optical lens 58 and the convex mirror 60 may be held by the holding mechanism.

  In addition, as described in the seventh embodiment, instead of disposing the optical path bending reflecting mirror 59 between the refractive optical lens 58 and the convex mirror 60, the first lens means and the second lens constituting the refractive optical lens 58 are provided. It is also possible to suppress the thickness of the image display device by bending the optical path by providing an optical path bending reflector between the lens means. FIG. 44 is a diagram showing the configuration of the image display apparatus at this time. The same or corresponding components as those in FIG. 42 are given the same reference numerals. Light from a micromirror device (not shown) passes through the first lens means of the refractive optical lens 58, is reflected by the optical path bending reflector 59, and then passes through the second lens means of the refractive optical lens 58. Then proceed to the convex mirror 60.

  In this case, the distance g is the longest distance from the convex mirror installation surface to the refractive optical lens. Further, in order to minimize the height of the lower portion of the screen, which is the distance from the lowermost end of the screen 18 to the optical axis 61, the reflected light beam 75 of the convex mirror 60 directed toward the lowermost end of the screen 18 is made as close as possible to the optical axis 61. In order to set it so as to pass through a low position, it is advantageous that the refractive optical lens 58 be separated from the convex mirror 60 as much as possible. In particular, when the reflected light beam 75 passes a position lower than the highest portion R of the exit surface of the refractive optical lens 58, the optical path is blocked by the refractive optical lens 58. For this reason, the shortest distance a from the convex mirror installation surface to the refractive optical lens 58 is set as long as possible within a range where the distance g does not exceed the thickness. From the above conditions, there is an optimum value for the distance f from the convex mirror installation surface to the exit pupil of the refractive optical lens 58 also in the case of FIG.

  Also, the optical path bending angle θ should be set as small as possible from the viewpoint of reducing the thickness, as in the case of using the optical path bending reflecting mirror between the lens and the convex mirror. However, if the bending angle θ is too small, the first lens means blocks the optical path from the optical path bending reflector to the second lens means. Therefore, it can be seen that there is an optimum value of the bending angle θ also in the case of FIG.

  In Embodiments 7 and 10, a prism may be used as the optical path bending means instead of the optical path bending reflector, and the same effect can be obtained.

Embodiment 11 FIG.
In the eleventh embodiment, the refractive light lens between the micromirror device and the reflecting mirror is configured to have a smaller diameter on the incident light side and the outgoing light side than the center portion of the lens, thereby satisfying the Petzval condition and bending. Explain how to construct an advantageous optical system

  FIG. 45 is a diagram showing a configuration of an image display apparatus according to Embodiment 11 of the present invention, and illustration of an illumination optical unit, a screen, and the like is omitted. 45, 14 is a micromirror device, 76 is a refractive optical lens (refractive optical unit), 77 is a convex mirror having a positive Petzval sum contribution component, 78 is an optical axis shared by the refractive optical lens 76 and the convex mirror 77, and 79 is This is a marginal ray of light traveling from the micromirror device 14 to the convex mirror 77.

  In the refractive optical lens 76, 80 is a positive lens having a positive power disposed at a high position of the marginal ray 79, 81 and 82 are an entrance lens group and an exit lens group of each positive lens 80, and a micromirror device. 14 is transmitted through the incident side lens group 81, the positive lens 80, and the output side lens group 82 in this order and travels toward the convex mirror 77.

  As described in the fifth embodiment, since the convex mirror 77 has a positive Petzval sum contribution component, the Petzval sum of the entire projection optical system tends to be a positive value, and field curvature occurs. Therefore, an increase in Petzval sum can be suppressed by reducing the power of the positive lens 80 constituting the refractive optical lens 76 having positive power as much as possible.

  The point of the eleventh embodiment is that the positive lens 80 is arranged at a high position of the marginal ray 79. In other words, if the power of the positive lens 80 is reduced in consideration of the Petzval condition, the effect of the lens action of the positive lens 80 is reduced accordingly. If a place where the marginal ray where the light spreads is high is selected, it is easy to associate each minute area of the entrance surface and the exit surface of the positive lens 80 with each light beam passing therethrough. Therefore, the shape of the entrance surface and the exit surface of the positive lens 80 with respect to the transmitted light can be designed more precisely, and the lens action of the low-power positive lens 80 can be made sufficiently effective.

  In this way, the negative lens 72 is disposed at a low marginal ray 71 so that the lens effect can be almost ignored. By disposing it at a high position of the marginal ray 79, it is possible to suppress an increase in Petzval sum without impairing the lens action of the positive lens 80.

  This will be specifically described with reference to FIG. In FIG. 45, the positive lens 80 at the center of the refractive optical lens 76 is a positive lens having positive power according to the eleventh embodiment, and is installed at a high position on the marginal ray 79. By installing the entrance side lens group 81 and the exit side lens group 82 of the positive lens 80, the marginal ray 79 in the positive lens 80 is increased.

  FIG. 46 shows a numerical example 11A of the eleventh embodiment. The specifications of FIG. 46 are f = −0.74 mm (focal length at a wavelength of 546.1 nm), NA = 0.17 (numerical aperture on the micromirror device side), and Yob = 14.2 mm (object height on the micromirror device side). ), M = 86.3 (projection magnification). The definition of the aspheric shape in FIG. 46 is the same as that described in Numerical Example 6A.

  When the result of the numerical calculation is verified, the height of the marginal ray 79 of the light incident on the refractive optical lens 76 is hi, and the maximum height of the marginal ray 79 of the light passing through the positive lens 80 at the center of the refractive optical lens 76 is hm. , If the height of the marginal ray 79 of the light emitted from the refractive optical lens 76 is ho, these hi, hm, and ho satisfy 1.05hi <hm <3hi and 0.3hi <ho <hi. It has become. In other words, since 0.3hi <ho <hi <hm / 1.05 <3 / 1.05 · hi, ho is the smallest in hi, hm, and ho that satisfy the above two inequalities.

  In addition, the configuration shown in FIG. 45 reduces the optical path from the optical path bending means to the reflection unit as described in the seventh embodiment by reducing the lens diameter of the emission part, in addition to the previous Petzval condition. Since it can be closer to the optical path than the case where the lens diameter is large in the range where it is not obstructed, there is also room for the insertion range of the optical path bending reflector. The positive lens 80 can also be configured by a plurality of lenses as shown in FIG. 53 according to Numerical Example 14A described later.

  As described above, according to the eleventh embodiment, the positive lens 80 having positive power is disposed at a high marginal ray 79 between the micromirror device 14 and the convex mirror 77, so that the Petzval sum of the optical system is obtained. Since the power of the positive lens 80 is reduced so as to suppress the increase of the positive lens 80, the positive Petzval sum contribution component of the projection optical system can be suppressed by effectively utilizing the lens action of the positive lens 80, and the field curvature The effect that the image display apparatus which reduced can be comprised is acquired.

  Further, the height hi of the marginal ray 79 of light incident on the refractive optical lens 76, the maximum height hm of the marginal ray 79 of light passing through the positive lens 80 at the center of the refractive optical lens 76, and the light emitted from the refractive optical lens 76 Since the height ho of the marginal ray 79 satisfies 1.05hi <hm <3hi and 0.3hi <ho <hi, the positive Petzval sum contribution component of the projection optical system can be suppressed, and the image plane The effect that an image display device with reduced curvature can be obtained is obtained.

  Further, if the relationship of 1.05 hi <hm <3 hi and 0.3 hi <ho <hi is satisfied, the lens diameter of the exit portion of the refractive optical lens 76 can be reduced, and the insertion range of the optical path bending reflector has a margin. The effect that an image display apparatus can be comprised is acquired.

Embodiment 12 FIG.
In the fourth embodiment, the effective display surface of the micromirror device 14 is shifted out of the optical axis of the odd-order aspheric surface and is eccentrically arranged, and is reflected while avoiding the center portion (point on the optical axis) of the odd-order aspheric surface. / The projection light beam (optical image signal) is guided onto the screen 18 through transmission. Since the vicinity of the optical axis center is not used, an odd-order aspheric surface can be used, which improves the degree of freedom of the aspheric convex mirror and improves the imaging performance. In Embodiment 12, the optical axis center is described. An example will be described in which the imaging performance in the optical axis direction in the peripheral portion is shifted from the imaging position in the optical axis direction in FIG.

  FIG. 47 is a diagram showing an imaging relationship of a general optical system. In FIG. 47, 14 is a micromirror device that is eccentrically arranged with respect to the optical axis, 83 is a refractive optical lens (projection optical means), 84 is a convex mirror (projection optical means), and 85 is an imaging position at the center of the optical axis. The imaging planes 86A and 86B, which are planes perpendicular to the optical axis, are imaging positions on the imaging plane 85 outside the optical axis.

  In the optical system of FIG. 47, if a plane is taken perpendicular to the optical axis with reference to the imaging position at the center of the optical axis, and this is defined as the imaging plane 85, the off-axis imaging positions 86A and 86B are also on the imaging plane 85. Design to exist. However, in a wide-angle optical system, it is difficult to keep the imaging position within the same plane, and the image plane is curved although there is a difference in the imaging position. Regarding this countermeasure, the optical system conditions that satisfy the Petzval conditions described in the fifth embodiment, the ninth embodiment, the eleventh embodiment, and the like have already been shown, and the technique for reducing the field curvature has been described.

  On the other hand, in the twelfth embodiment, since the center of the optical axis is not used, the imaging position of this portion may be different from the off-axis imaging position actually used. FIG. 48 shows an example of an optical system having a curved image surface. 87 is a refractive optical lens, 88 is a convex mirror, 89 is a curved image surface, and 90A and 90B are off-axis imaging positions.

  The point of the twelfth embodiment is that the field curvature as shown by the curved image plane 89 is allowed as shown in FIG. Under this condition, a lens configuration that deviates from the Petzval condition is possible, and the conditions for limiting the refractive index and dispersion of the optical material constituting the refractive optical lens 87 are relaxed, so that the degree of freedom in design is expanded. For this reason, it can be seen that higher imaging performance is easily obtained.

  As described above, according to the twelfth embodiment, since the imaging position at the center of the optical axis is removed from the same plane where the imaging positions around the optical axis exist, design freedom of the refractive optical lens 87 can be reduced. As a result, the image display apparatus having an excellent imaging performance can be configured.

Embodiment 13 FIG.
In the thirteenth embodiment, in addition to the method for reducing the curvature of field shown in the fifth embodiment, a method for further reducing the curvature of field will be described.

  As shown in the above numerical examples, the shape of the convex mirror tends to be a shape in which the peripheral portion is warped. Paying attention to the local curvature of the convex mirror, even if the curvature of the convex mirror at the center of the optical axis is convex, the curvature of the convex mirror at the curved portion is concave. Light is diverged by a convex mirror, and light is collected by a concave mirror. Therefore, to form an image on the screen, the light emitted from the refractive optical unit incident on the convex mirror is centered on the optical axis. Therefore, convergent light is required, and divergent light is required in the periphery.

  Considering that a lens that generates convergent light at the center of the optical axis also generates convergent light at the periphery, it can be easily estimated that it is very difficult to design a refractive optical lens that meets this condition. In other words, when a general refractive optical lens is used, a large curvature of field occurs. Therefore, suppressing the curvature of the peripheral portion of the convex mirror has a great effect on suppressing the curvature of field. In the thirteenth embodiment, it is shown that the curvature of the convex mirror periphery can be suppressed by giving pupil aberration to the exit pupil of the refractive optical lens. The reason is shown below.

  FIG. 49 shows the structure of an image display device according to Embodiment 13 of the present invention. In FIG. 49, 91 is a refractive optical lens (refractive optical part), 92 is a convex mirror whose peripheral part is warped, 93 is a convex mirror whose peripheral part is improved, and 94 is shared by the refractive optical lens 91 and the convex mirrors 92 and 93. The optical axis, 95 is outgoing light in the vicinity of the optical axis, 96 is outgoing light in the peripheral portion, 97 is the exit pupil of the refractive optical lens 91 for the outgoing light 95 in the vicinity of the optical axis, and 98 is the refractive optical lens for the outgoing light 96 in the peripheral portion. Reference numeral 91 denotes an exit pupil, and 99 denotes light emitted from the peripheral portion when the light exits from the exit pupil 97.

  In general, the light emitted from the refractive optical lens 91 is emitted from the exit pupil 97, like the emitted light 95 that has passed through the vicinity of the optical axis 94 in FIG. Here, as can be seen from the relationship between the outgoing light 96, the convex mirror 92, and the convex mirror 93 in FIG. 49, the exit pupil 96 is at the position 97 in order to reflect the outgoing light 96 by the convex mirror 92 and correct the distortion. Although it is good, the exit near the center of the optical axis 94 as in the exit pupil 98 can be obtained in such a way that the exit mirror 96 is reflected by the convex mirror 93 and the distortion is corrected. What is necessary is just to deliberately shift the pupil 97 and the exit pupil 98 of the light emitted from the peripheral portion as shown in FIG.

  As described above, by adjusting the incident position and the incident angle of the light to the convex mirror 93, it is possible to suppress warping at the end portion like the convex mirror 93 and to suppress curvature of field. Is obtained. This feature is recognized in all the numerical examples described above.

Embodiment 14 FIG.
In the fourteenth embodiment, a method for improving the imaging performance by allowing distortion aberration near the center of the optical axis in the projection optical unit will be described.

  50 is a diagram showing a configuration of an image display apparatus according to Embodiment 14 of the present invention. 50, reference numeral 100 denotes a screen, 101 denotes an optical axis shared by the projection optical system (not shown) and the screen 100, and 102 denotes a maximum range where a circle centered on the optical axis 101 intersects only at the bottom of the screen 100. It is.

  In the optical system, the distortion aberration is a major factor that defines the imaging performance. Therefore, the imaging performance can be improved by removing this restriction. However, when distortion occurs, the image around the screen is displayed distorted with respect to the screen frame, or the image is displayed too large or too small than the side of the screen frame. In order to reduce these problems as much as possible, it is necessary to suppress the portion affected by the distortion as much as possible.

  As shown in a range 102 on the screen 100 in FIG. 50, when a circle is drawn around the optical axis 101, the projection optical unit is generated up to a range that intersects the bottom of the screen 100 and does not intersect with other sides. By making the absolute value of the distortion aberration to be large and suppressing the absolute value of the distortion aberration small in the region outside this circle, the influence of the distortion aberration can be limited to the bottom side of the screen 100, and the other three sides are correct rectangles. Images can be formed into shapes.

  Further, the distortion generated in the optical system is defined by the ratio of distortion to the distance from the optical axis. In other words, even when the distortion aberration value is the same, the closer the distance from the optical axis, the smaller the actual amount of distortion. Also, from a visual point of view, the image distortion is difficult to understand for the video inside the screen, and can be easily determined when the outermost peripheral portion of the screen is distorted and the screen boundary portion, which is originally a straight line, becomes a curve. According to the present invention, distortion occurs on one side close to the optical axis and the linearity of this side is lost, but since the distance from the optical axis to this one side is short, the relative amount of distortion with respect to the other side is reduced, The effect that the boundary portion is not easily curved is obtained. Further, if there is an optical axis on this side, the linearity is not lost with respect to the outer surface boundary portion.

  This feature is particularly effective when the display is used in a multi-configuration. FIG. 51 is a diagram showing an image display device when used in a multi-configuration. In FIG. 51, 100A to 100F are screens, 101A to 101F are optical axes shared by the projection optical units (not shown) and the screens 100A to 100F, and 102A to 102F are circles centered on the optical axes 101A to 101F. Shows the maximum range where only the bottom sides of the screens 100A to 100F intersect.

  As shown in FIG. 51, even when a multi-display having two screens in the vertical direction and multiple screens in the horizontal direction is configured, if the distortion of the portion excluding the bottom is suppressed, the overlapping of the picture at the connecting part of the screen, the gap between the pictures Almost no such thing occurs.

  The above configuration is a result derived by numerical calculation. Specific numerical calculation results are shown as Numerical Example 14A.

<Numerical Example 14A>
52 and 53 are diagrams showing numerical data and configuration of Numerical Example 14A, respectively. The specifications of FIG. 52 are f = 3.31 mm (focal length at a wavelength of 546.1 nm), NA = 0.17 (numerical aperture on the micromirror device side), and Yob = 14.65 mm (object height on the micromirror device side). , M = 86.96 (projection magnification).

  FIG. 54 shows the numerical calculation results of the distortion aberration in the numerical example 14A. As a comparison with the design allowing distortion, FIG. 55 shows the distortion of Numerical Example 4A. As can be seen from FIG. 55, the distortion in numerical example 4A is approximately 0.1% or less, whereas the distortion in numerical example 14A shown in FIG. 54 has a small image height indicating the distance from the optical axis. It can be seen that a maximum of 2% distortion is allowed in the range.

  Note that the distortion generated in the optical system as a result of the design that allows distortion can be corrected by changing the shape of the mirror surface used for optical path bending or the like. That is, if the shape of the plane mirror 22 that reflects the light from the projection optical system 17 and folds the optical path to the screen 18 is distorted so as to correct the distortion, the distortion of the entire image display apparatus can be corrected. Can do.

Embodiment 15 FIG.
In the fifteenth embodiment, two devices are applied to the convex mirror. One device can improve environmental characteristics with respect to temperature change, and the other device can facilitate alignment adjustment in the assembly process of the image display apparatus.

  FIG. 56 is a diagram showing the structure of an image display device according to Embodiment 15 of the present invention. FIG. 56A is a side view of the image display device, and illustration of an illumination optical system, a screen, and the like is omitted. FIGS. 56B and 56C are a top view and a front view of the convex mirror, respectively. In FIG. 56, the z axis is taken in the direction of the optical axis of the convex mirror, the x axis is taken to be perpendicular to the z axis in the horizontal plane including the optical axis, and the y axis is taken to be perpendicular to the x axis and the z axis. .

  In FIG. 56, reference numeral 14 denotes a micromirror device, 103A and 103B denote refractive optical lenses (refractive optical parts) shown in the respective embodiments, 104 denotes a convex mirror (reflecting part) characterizing the fifteenth embodiment, and 105 denotes refractive optics. This is the optical axis shared by the lenses 103A and 103B and the convex mirror 104. The convex mirror 104 forms the convex mirror 104 by cutting a non-reflective portion 104C from a rotationally symmetric convex mirror 104O around the optical axis 105 (see FIGS. 56B and 56C, Embodiment 10).

  In the convex mirror 104, 104F is a front surface as a reflecting surface of the convex mirror 104 that reflects light from the refractive optical lenses 103A and 103B, and 104R is a rear surface of the convex mirror 104 provided on the back side of the front surface 104F.

  In the present invention, since the aspherical shape of the front surface 104F is designed by precise ray tracing in order to correct distortion, the degree of contraction or expansion differs for each part of the convex mirror 104 depending on the temperature change of the usage environment. When this occurs, the shape of the front surface 104F changes slightly, affecting the correction of distortion. As a countermeasure against this temperature change, the point that the thickness from the front surface 104F to the rear surface 104R is made uniform is the first device applied to the convex mirror 104.

  57A and 57B are diagrams for explaining the shape change in the thickness direction of the convex mirror with respect to the temperature change. FIG. 57A shows the convex mirror 104 that contracts, and FIG. 57B shows the convex mirror 104 that expands. The same or corresponding components as those in FIG. 56 are given the same reference numerals.

  Since the convex mirror 104 is manufactured with a material having a uniform linear expansion coefficient, the thickness change of the convex mirror 104 with respect to the temperature change is all at each part by making the thickness from the front surface 104F to the rear surface 104R uniform. Will be equal. Therefore, each part of the front surface 104F (broken line) and the rear surface 104R (broken line) manufactured by designing the surface shape by ray tracing contracts and expands in parallel to the optical axis 105, and the front surface 104F ′ (solid line). ) And the rear surface 104R ′ (solid line). Since the thickness change of the convex mirror 104 is the same in each part, the front surface 104F 'maintains the shape of the front surface 104F, and the shape change of the front surface 104F with respect to the environmental temperature change can be suppressed.

  Another contrivance applied to the convex mirror 104 is that a low reflection surface 104L and a high reflection surface 104H are formed in the vicinity of the optical axis 105 of the front surface 104F (FIG. 56). The reflectance of the low reflection surface 104L is set to be considerably lower than the reflectance of the high reflection surface 104H.

In the convex mirror 104 of the image display apparatus of the present invention in which the micromirror device 14 is eccentrically arranged with respect to the optical axis 105, the vicinity of the optical axis 105 (non-projection front surface) of the front surface 104F is used for reflection of light to the screen or the plane mirror. Therefore, the low reflection surface 104L and the high reflection surface 104H are provided in the vicinity of the optical axis 105 of the front surface 104F.
For example, the vicinity of the optical axis 105 of the front surface 104F passes through the optical path closest to the optical axis 105 between the refractive optical lens 103B and the convex mirror 104 in the cross-sectional view of FIG. 56A including the optical axis 105 and orthogonal to the x axis. This corresponds to a portion of the light beam 106 that is lower than the reflection point 106P on the front surface 104F.

  The low reflection surface 104 </ b> L and the high reflection surface 104 </ b> H are not aspherical, but are formed on a small plane perpendicular to the circular (semicircle) optical axis 105 centered on the optical axis 105. Assuming that the distance from the intersection of the front surface 104F and the optical axis 105 to the reflection point 106P is R, values rL and rH smaller than R are the radii of the low reflection surface 104L and the high reflection surface 104H, respectively, and the optical axis 105 is the center. The low reflection surface 104L and the high reflection surface 104H are formed by concentric circles (semicircles). Since rL> rH is set, the high reflection surface 104H exists inside the low reflection surface 104L, and the high reflection surface 104H is closer to the optical axis 105 than the low reflection surface 104L.

By providing the low reflection surface 104L and the high reflection surface 104H on the convex mirror 104, alignment adjustment in the assembly process of the image display apparatus can be facilitated.
FIG. 58 is a diagram showing an alignment adjustment method using the convex mirror 104. The same reference numerals as those in FIG. 56 denote the same configurations.

  In FIG. 58, reference numeral 107 denotes a laser that outputs laser light having high straightness (straight-ahead light), 108 denotes an isolator that passes the laser light from the laser 107 only in one direction and returns the laser 107 to protect it from laser light, 109 A half mirror 110 provided between the isolator 108 and the convex mirror 104 is a detector that detects the power of laser light from the half mirror 109. In addition, arrows with reference numerals 111 and 112 are the forward and return laser beams during alignment adjustment, respectively, and a two-dot broken line with reference numeral 113 is a virtual optical axis created by the laser lights 111 and 112.

  First, the virtual optical axis 113 for the convex mirror 104 is set with the configuration of FIG. Laser light emitted from the laser 107 parallel to the horizontal plane passes through the isolator 108 and the half mirror 109 and travels toward the convex mirror 104. At this time, the orientation of the convex mirror 104 with respect to the translation adjustment Mx in the x-axis direction, the rotation adjustment Rx around the x-axis, the translation adjustment My in the y-axis direction, and the rotation adjustment Ry around the y-axis is finely adjusted with a manipulator or the like. The laser beam 111 is reflected by the highly reflective surface 104H so that the power of the laser beam 112 detected by the detector 110 via the half mirror 109 is maximized.

  The state in which the maximum power is detected is when the convex mirror 104 is in the most desirable posture, that is, the forward laser beam 111 from the half mirror 109 to the convex mirror 104 and the backward laser beam from the convex mirror 104 to the half mirror 109. This is a case where 112 completely matches. When the highly reflective surface 104H of the plane mirror having high reflectivity is made orthogonal to the laser beam 111, the laser beam is highly straight, so that the laser beams 111 and 112 are completely matched to create the virtual optical axis 113. it can.

  When the posture of the convex mirror 104 is largely deviated, the laser beam 112 reflected by the convex mirror 104 does not enter the detector 110 via the half mirror 109, and thus the detector 110 does not detect power. Further, even if the posture of the convex mirror 104 approaches a desired state, the low reflection surface 104L of the plane mirror reflects the laser light 111 to the half mirror 109 if there is an optical axis shift. Since the reflectivity of the low reflection surface 104L is low, the power of the laser beam 112 detected by the detector 110 via the half mirror 109 is at a low level, so that an optical axis shift can be detected. Considering this method, it can be seen that the value of the radius rH of the highly reflective surface 104H may be determined from the allowable range of the optical axis deviation.

  Further, the light receiving surface of the detector 110 is divided into a “field shape” (two rows and two columns matrix, FIG. 58 (c)) by four light receiving elements 110A, 110B, 110C, and 110D. By performing differential calculation of the output signal of 110D, the inclinations Rx and Ry of the convex mirror 104 can be detected and adjusted with high accuracy.

  Further, the total optical power incident on the light receiving element can be obtained by adding the outputs of the four divided light receiving elements 110A to 110D, and the optical axis deviations Mx and My can be detected. Therefore, with this configuration, total adjustment of Mx, My, Rx, and Ry can be performed.

  In this way, by monitoring the laser beam 112 detected by the detector 110 and finely adjusting the posture of the convex mirror 104, the virtual optical axis 113 by the laser beams 111 and 112 can be created.

  Next, alignment adjustment of the refractive optical lenses 103A and 103B is performed with the configuration of FIG. Refractive optical lenses 103A and 103B are inserted into the configuration in which the virtual optical axis 113 in FIG. Also in this case, when the postures of the refractive optical lenses 103A and 103B are desired, the laser beams 111 and 112 pass through the centers of the refractive optical lenses 103A and 103B.

  That is, when the laser beams 111 and 112 pass orthogonally to the centers of the refractive optical lenses 103A and 103B, no lens action is given to the laser light 112 of the refractive optical lenses 103A and 103B. It is obtained with. This desirable state corresponds to the case where the optical axes of the refractive optical lenses 103A and 103B coincide with the virtual optical axis 113.

  As described above, according to the fifteenth embodiment, since the convex mirror 104 having the equal thickness from the front surface 104F to the rear surface 104R is provided, the shape change of the front surface 104F with respect to the temperature change can be suppressed. And the environmental characteristics of the image display device can be improved.

  Further, according to the fifteenth embodiment, the low reflection surface 104L provided in the vicinity of the optical axis 105 of the front surface 104F, and the allowable range of the optical axis deviation closer to the optical axis 105 of the front surface 104F than the low reflection surface 104L. Since the convex mirror 104 is provided with the highly reflective surface 104H having the size of ## EQU3 ##, the virtual optical axis 113 can be created by power monitoring and calculation processing by the detector 110, and in the assembly process of the image display device Thus, the effect that the alignment of the convex mirror 104 and the refractive optical lenses 103A and 103B can be easily adjusted is obtained.

Embodiment 16 FIG.
FIG. 59 shows the structure of an image display device according to Embodiment 16 of the present invention. Illustration of an illumination light source system, a plane mirror, a screen, and the like is omitted.
In FIG. 59, 14 is a micromirror device (transmission means), 114 is a cover glass (transmission means) that protects the reflective surface (outgoing surface) of the micromirror device 14, and 115 is a variation in the optical thickness of the cover glass 114. Compensation glass (transmitting means) for compensation, 76 and 77 are the refractive optical lens (refractive optical part) and convex mirror (reflecting part) shown in each embodiment, and 78 is the optical axis of the refractive optical lens 76 and convex mirror 77. .

  The micromirror device 14 is mounted with a cover glass 114 for protecting a reflection surface composed of a large number of small mirrors. Light from an illumination light source system (not shown) composed of a light emitter, a paraboloid reflector, a condenser lens, and the like is incident on the reflection surface via the cover glass 114. The light whose intensity is modulated by the reflecting surface passes through the cover glass 114 and then travels toward the refractive optical lens 76 and the convex mirror 77.

  By the way, the thickness of the cover glass 114 is not always a constant reference value, and is manufactured within a range of a so-called tolerance between a maximum dimensional thickness and a minimum dimensional thickness. Therefore, it is normal that individual differences occur in the thickness of the cover glass 114. In addition, it may be assumed that the thickness reference value will be changed in the future. Since the light used for the image display device always passes through the cover glass 114, the thickness variation due to individual differences in thickness and changes in the specification of the reference value affects the light passing through the cover glass 114. Thus, the optical path design of the entire optical system depends on the difference in the thickness of the cover glass 114.

In the sixteenth embodiment, a compensation glass 115 is provided between an illumination light source system (not shown) or the refractive optical lens 76 and the cover glass 114 in order to compensate for variations in the thickness of the cover glass 114.
Next, a method for compensating for individual differences in the thickness of the cover glass 114 by the compensation glass 115 will be described with reference to FIG.

  FIG. 60 is a diagram showing the relationship between the thickness of the cover glass 114 and the thickness of the compensation glass 115. Here, for simplicity of explanation, the refractive index n1 of the cover glass 114 and the refractive index n2 of the compensation glass 115 are assumed to be equal (n1 = n2 = n), but as will be described later, the refractive index n1. , N2 may be different.

* Reference State FIG. 60A shows the case where the thickness t1 of the cover glass 114 is the reference value T1. At this time, light is exchanged with the micromirror device 14 on which the cover glass 114 is mounted via the compensation glass 115 having a thickness t2 = T2. Therefore, this light passes equivalently through a glass medium having a thickness t = T1 + T2 and a refractive index n. Other optical systems such as the illumination light source system, the refractive optical lens 76, and the convex mirror 77 are designed on the assumption that a glass medium having a thickness t = T1 + T2 and a refractive index n exists.

* Compensation example 1
FIG. 60B shows a case where the thickness t1 of the cover glass 114 is T1 + ΔT, which is shifted from the reference value T1 by an individual difference ΔT (ΔT includes a positive / negative sign). At this time, light is exchanged with the micromirror device 14 on which the cover glass 114 is mounted through the compensation glass 115 having a thickness t2 = T2−ΔT.

  That is, since the total value of the thickness t1 = T1 + ΔT of the cover glass 114 and the thickness t2 = T1−ΔT of the compensation glass 115 is the same thickness t = T1 + T2 as in the above-described reference state, the micromirror device 14 is exchanged. Light passes equivalently through a glass medium having a thickness t = T1 + T2 and a refractive index n. Therefore, even though the variation ΔT is caused by the difference in the thickness t1 of the cover glass 114, the variation ΔT is canceled by changing the thickness t2 of the compensation glass 115, and the optical system in the reference state is designed. Can be used without change.

* Compensation example 2
FIG. 60C shows a case where the specification of the thickness t1 of the cover glass 114 is changed from the reference value T1 to the reference value T3. At this time, assuming that ΔT of compensation example 1 is T3−T1, the micromirror device 14 on which the cover glass 114 is mounted via the compensation glass 115 of thickness t2 = T2− (T3−T1) = T2−ΔT. And exchange light.

  Similar to the compensation example 1, the total value of the thickness t1 = T1 + (T3−T1) = T1 + ΔT of the cover glass 114 and the thickness t2 = T2− (T3−T1) = T2−ΔT of the compensation glass 115 is as described above. Therefore, t = T1 + T2 which is the same as the reference state of FIG. 5, and thus the light exchanged with the micromirror device 14 passes equivalently through a glass medium having a thickness t = T1 + T2 and a refractive index n. Therefore, although the thickness deviation ΔT is caused by the change in the specification of the cover glass 114 from the reference value T1 to the reference value T3, the thickness deviation ΔT is changed to the thickness t2 of the compensation glass 115. Can be used without changing the design of the optical system in the reference state.

  As can be seen from the above reference state and compensation examples 1 and 2, in the sixteenth embodiment, according to the increase or decrease in variation (or thickness deviation) ΔT from the reference value T1 of the thickness t1 of the cover glass 114, The reference value T2 of the thickness t2 of the compensation glass 115 is decreased by a variation (or thickness deviation) ΔT so that the total value t = T1 + T2 is constant, so that the refractive index n and the thickness t = It can be considered that the glass medium of T1 + T2 is equivalently mounted on the reflection surface of the micromirror device 14, and the optical system in the reference state is used as it is without being influenced by variation (or thickness deviation). be able to. Of course, this Embodiment 16 can be applied not only to the micromirror device 14 but also to other spatial light modulation elements such as liquid crystal.

  In the above, the cover glass 114 and the compensation glass 115 have been considered as having the same refractive index n. However, as the cover glass 114 and the compensation glass 115 have different refractive indices n1 and n2, the refractive indices n1 and n2 are also It is more common to consider the added optical thickness.

  That is, considering the optical thickness t1 / n1 of the cover glass 114 and the optical thickness t2 / n2 of the compensation glass 115, the compensation glass 115 satisfies the condition of “t1 / n1 + t2 / n2 = constant”. Thickness t2 and refractive index n2. In this way, variations in the thickness t1 and the refractive index n1 of the cover glass 115 can be compensated.

  Further, if a configuration (compensation glass attaching / detaching mechanism) in which the compensation glass 115 can be attached to and detached from the incident side (micromirror device 14 side) of a lens barrel (not shown) that holds the refractive optical lens 76 (refractive optical unit), the cover glass 114 is provided. Accordingly, the compensation glass 115 can be appropriately replaced with the optimum thickness in accordance with the thickness change and the thickness variation.

<Numerical Example 16A>
The numerical calculation results when the compensation glass 115 is used are also disclosed here.
61 and 62 are diagrams showing numerical data and configuration of Numerical Example 16A, respectively. 45 and 59 are the same or corresponding components. The specifications in FIG. 61 are f = 3.39 mm (focal length at a wavelength of 546.1 nm), NA = 0.17 (numerical aperture on the micromirror device side), and Job = 14.65 mm (object height on the micromirror device side). , M = 86.96 (projection magnification). Since the cover glass 114 is included in the compensation glass 115 and calculated, it is shown in FIG.

  In the numerical data shown in FIG. 61, the thickness of the second surface is 4.5 mm as the sum of the cover glass 114 and the compensation glass 115. For example, it is a result of aberration correction assuming a situation where the reference thickness of the cover glass is 3 mm and the thickness of the compensation glass is 1.5 mm.

  As described above, according to the sixteenth embodiment, due to manufacturing tolerances and design changes between the cover glass 114 mounted on the reflective surface of the micromirror device 14 and the refractive optical lens 76 and the illumination light source system. According to the variation in the optical thickness of the cover glass 114 that increases or decreases, a compensation glass 115 having an optical thickness obtained by conversely reducing the variation is provided so that light is exchanged with the reflecting surface of the micromirror device 14. Therefore, it can be considered that the reflection surface of the micromirror device 14 is always protected by the glass medium having a constant optical thickness by offsetting the variation in the thickness of the cover glass 114, and the illumination light source system The refractive optical lens 76 and the convex mirror 77 can be used without changing the design.

  According to the sixteenth embodiment, since the compensation glass 115 can be attached to and detached from the incident side (micromirror device 14 side) of a lens barrel (not shown) that holds the refractive optical lens 76, the cover glass is provided. An effect is obtained that the compensation glass 115 can be appropriately replaced with the optimum thickness corresponding to the thickness change or thickness variation of 114.

Embodiment 17. FIG.
FIG. 63 is a diagram showing a configuration of an image display device using the plane mirror 22 (FIG. 4) of the first embodiment and the optical path bending reflector 59 (FIG. 23, etc.) of the seventh and tenth embodiments. FIG. Components identical or corresponding to those in FIGS. 4 and 23 are given the same reference numerals. Further, illustration of a condensing optical system including an illumination light source system, a micromirror device, a refractive optical lens, and the like is omitted.

  In FIG. 63, reference numeral 116 denotes a rectangular parallelepiped image display device, 117 denotes a lower part of the screen of the image display device 116, 118 denotes a horizontal bottom surface of the image display device 116, a surface provided with the screen 18 and the convex mirror 60, and the plane mirror 22. Is perpendicular to the bottom surface 118. In FIG. 63, the image display device 116 is cut in half by a plane including the optical axis 61 and orthogonal to the bottom surface 118. The ξ axis is taken in the normal direction of the screen 18, the ψ axis is taken in the normal direction of the bottom surface 118, and the ζ axis is taken in a direction orthogonal to the ξ and ψ axes.

  119 is a light beam reflected by a point P (third point) on the convex mirror (reflecting part) 60 and directed to a point Q (second point) on the plane mirror 22, and 120 is reflected by a point Q on the plane mirror 22. It is a light ray directed to a point R (first point) on the screen (display means) 18. A point R exists on the bottom of the quadrangular image displayed on the screen 18 (a side parallel to the bottom surface 118 and close to the bottom surface 118), and is the point farthest from the center of the image. Reference numerals 121 and 122 denote line segments when light rays 119 and 120 are projected from the ψ-axis direction onto the bottom surface 118, and points P ′, Q ′, and R ′ (third, second, and first projected points, respectively) are The points P, Q, and R are projected from the ψ axis direction onto the bottom surface 118, respectively.

  At this time, when a space (arrangement space) S composed of points P, Q, R, P ′, Q ′, and R ′ is extracted, the result is as shown in FIG. In the seventeenth embodiment, attention is paid to the space S as an arrangement space for the condensing optical system or the like, so that the height of the screen lower portion 117 is not increased. Since the light rays 119 and 120 are light rays corresponding to the point R, when arranging the components of the condensing optical system in the space S, care should be taken not to shine the light rays 119 and 120. It will not be.

  64 is a diagram showing the configuration of an image display device according to Embodiment 17 of the present invention. FIG. 64 (a) is a front view of a portion below the lower end of the screen of the image display device 116 as seen from the ξ-axis direction. 64 (b) is a top view of the image display device 116 viewed from the ψ-axis direction. The same reference numerals as those in FIGS. 1, 4, 23 and 63 denote the same or corresponding structures. FIGS. 65A and 65B are cross-sectional views of the image display device 116 taken along planes A-A ′ and B-B ′ orthogonal to the screen 18. The B-B ′ plane is a plane closer to the line segment Q-Q ′ than the A-A ′ plane.

  In FIG. 64, reference numeral 123 denotes an illumination light source system (transmitting means, illumination light source unit, main part of the collection optical system) including the light emitter 11, the parabolic mirror 12, and the condenser lens 13. A color wheel (transmission means, main part of the condensing optical system) for sequentially coloring (illuminating light) into the three primary colors, 125 receives light from the color wheel 124 at the incident surface, and emits light with a uniform illuminance distribution. Reference numeral 126 denotes a rod integrator (transmitting means, main part of the condensing optical system) that emits light from the relay lens (transmitting means, main part of the condensing optical system) that relays light from the rod integrator 125.

  Reference numerals 127 and 128 respectively denote a second optical path bending reflector (second optical path bending means) and a third optical path bending reflector (third optical path bending means) that characterize the seventeenth embodiment. Reference numeral 129 denotes a field lens (transmission unit) that enters the micromirror device (transmission unit, reflection type image information providing unit) 14 with the principal ray direction of light from the relay lens 126 aligned. The light from the relay lens 126 is sequentially reflected by the second and third optical path bending reflectors 127 and 128 and travels toward the field lens 129.

  A condensing optical system for condensing light onto the micromirror device 14 includes an illumination light source system 123, a color wheel 124, a rod integrator 125, a relay lens 126, a second optical path bending reflector 127, and a third optical path bending reflection. The illumination light source system 123, the color wheel 124, the rod integrator 125, and the relay lens 126 are particularly referred to as a condensing optical system main part.

  130 is an optical axis shared by the main part of the condensing optical system, 131 is a surplus space of the image display device 116, and when the normal image display device 116 is constructed, the surplus space 131 is cut off. Not considered as a placement space. In FIG. 64, the main part of the condensing optical system is disposed in the space S with the optical axis 130 parallel to the bottom surface 118 of the image display device 116 and the light receiving surface of the screen 18.

  One reason for this is that, as shown in FIG. 66, when the illumination light source system 123 having the optical axis 130 on the horizontal plane is tilted to become the illumination light source system 123A of the optical axis 130A, the optical axis 130 and the optical axis. When the angle θ formed by 130A exceeds a specified value (for example, 15 °), the internal temperature distribution of the light emitter 11 (short arc discharge lamp) constituting the illumination light source system 123 deviates from the specified state, and the illumination light source system 123 This is because the lifetime is shortened. The illumination light source system 123 does not cause a problem with respect to the rotational movement about the optical axis 130.

  67, as shown in FIG. 67, the image display device 116 is not limited to the usage form (FIG. 67 (a)) in which the bottom surface 118 is horizontal. For example, the image display device 116 is used as a wall-hanging image display device. In addition, a usage mode in which the bottom surface 118 is slightly tilted from the horizontal plane (FIG. 67 (b)), a usage mode in which the bottom surface 118 is tilted slightly from the horizontal plane by turning upside down (FIG. 67 (c)), and the like are also assumed. Because.

  In addition to the above two reasons, the image display device 116 is reduced in thickness (minimization of the size in the ξ-axis direction) and the height of the screen lower part 117 is suppressed (minimization of the screen lower part 117 in the ψ-axis direction). Further, the arrangement configuration shown in FIG. 64 is adopted. In this way, even when the image display device 116 is tilted as shown in FIGS. 67B and 67C, the illumination light source system 123 has a rotational motion around the optical axis 130. Various usage forms of the image display device 116 can be handled without deteriorating the life of the light source system 123. At this time, as shown in FIG. 65, large components are arranged in a region closer to the BB ′ plane than to the AA ′ plane so as not to shine light (shaded portions) from the convex mirror 60 toward the screen 18. To do.

  By the way, as described in the seventh and tenth embodiments, the plane mirror 22 is installed in parallel to the screen 18, and the optical path bending reflector 59 and the convex mirror 60 appropriately disposed with respect to the plane mirror 22 are provided. The positions of the refractive optical lens 58 and the micromirror device 14 are determined from the positions. Therefore, the second and third optical path bending reflectors 127 and 128 are connected to the relay lens 126 and the field lens 129 in order to make the light from the main part of the condensing optical system installed in the space S incident on the micromirror device 14. Light is mediated between them. The second optical path bending reflector 127, which is higher than the third optical path bending reflector 128, is installed at a position as low as possible so that the light emitted from the convex mirror 60 is not vignetted.

  The reason why the position between the relay lens 126 and the field lens 129 is selected as the arrangement position of the second and third optical path bending reflectors 127 and 128 is that the mutual positional relationship between other components is optical such as imaging. This is because the optical path length from the relay lens 126 to the field lens 129 can be appropriately determined by adjusting the focal length of the relay lens 126 and the focal length of the field lens 129, although it is determined by the conditions. .

  In this way, the main part of the condensing optical system is arranged in the space S with the optical axis 130 parallel to the bottom surface 118 and the screen 18 of the image display device 116, and the second and third optical path bending reflectors 127 and 128 are arranged. Thus, the light from the relay lens 126 to the field lens 129 is mediated so that the light can be condensed from the main part of the condensing optical system in the space S onto the micromirror device 14 which is a reflective spatial light modulator. .

  Furthermore, in order to suppress the height of the screen lower portion 117, the following may be performed. That is, when the optical axis 130 is installed in parallel with the bottom surface 118, the height of the screen lower portion 117 (position of the bottom surface 118 in the ψ-axis direction) is increased by components having large diameters such as the illumination light source system 123 and the color wheel 124. It is also assumed that it is determined. Therefore, as shown in FIG. 68, the optical axis 130B of the main part of the condensing optical system including the illumination light source system 123B, the color wheel 124B, the rod integrator 125B, and the relay lens 126B is inclined at an inclination angle θ. Of course, the inclination angle θ is within the specified value of the illumination light source system 123B.

  The optical axis 130B is parallel to the light-receiving surface of the screen 18, and the intersection of the illumination light source system 123B and the optical axis 130B is higher in the ψ-axis direction (vertical direction) than the intersection of the relay lens 126B and the optical axis 130B. To incline. In this case, care should be taken that the inclination angle θ is kept within a specified value and the light rays 119 and 120 are not vignetted by the illumination light source system 123B and the color wheel 124B. As the optical axis 130B is inclined, the position of the second optical path bending reflector 127B in the ψ-axis direction is lowered, and the positions of the illumination light source system 123B and the color wheel 124B in the ψ-axis direction are increased. The height of the screen lower portion 117 is determined by the third optical path bending reflector 128 at the lowest position.

  Further, in the above state, a storage hole 133 for storing the third optical path bending reflector 128 is provided in the adjustment stand 132 that is disposed below the condensing optical system and holds each component and adjusts its installation position. It may be provided (FIG. 69). This makes it possible to further suppress the height of the screen lower portion 117.

  In the above description, the second and third optical path bending reflectors 127 and 128 have been treated as plane mirrors. However, the seventeenth embodiment is not limited to this, and two or one curved mirror is used. You may make it use. By using at least one of the second and third optical path bending reflecting mirrors 127 and 128 as a curved mirror and devising the curved reflecting surface (optical surface), a degree of freedom can be given to control the light beam. Become.

  Similarly to the optical path bending reflector 59 of the seventh and tenth embodiments, at least one of the second and third optical path bending reflectors 127 and 128 is a prism having a planar or curved refracting surface (optical surface). Anyway.

  By doing in this way, the illumination efficiency to the micromirror device 14, the imaging condition of the exit surface of the rod integrator 125 to the micromirror device 14, the Fourier transform surface of the relay lens 126 system to the entrance pupil of the refractive optical lens 58 Various optical performance improvements such as imaging conditions and uniform illumination distribution of illumination light from the micromirror device 14 can be achieved.

  As described above, according to the seventeenth embodiment, a ray R that exists on the bottom of the quadrangular image displayed on the screen 18 and is farthest from the center of the image, and a light beam that travels from the plane mirror 22 to the point R. 120, the reflection point Q on the plane mirror 22, the reflection point P on the convex mirror 60 of the light beam 119 from the convex mirror 60 toward the reflection point Q, and the points P, Q, R from the normal direction of the horizontal bottom surface 118 to the bottom surface 118. The main part of the condensing optical system (in the example of FIG. 64, from the illumination light source system 123 to the relay lens 126) is arranged in a space S formed by connecting the projected points P ′, Q ′, and R ′ with line segments. As a result, the height of the screen lower portion 117 can be suppressed within the range of the thinness of the image display device determined by the plane mirror 22 and the screen 18.

  Further, according to the seventeenth embodiment, the second optical path bending reflector 127 that reflects the light from the main part of the condensing optical system from the illumination light source system 123 to the relay lens 126, and the second optical path bending. Since the third optical path bending reflecting mirror 128 that makes the reflected light from the reflecting mirror 127 incident on the micromirror device 14 through the field lens 129 is provided, the micromirror device 14 that is a reflective light spatial modulation element. On the other hand, the effect that light can be condensed by the main part of the condensing optical system arranged in the space S is obtained.

  Furthermore, according to the seventeenth embodiment, since the optical axis 130 of the main part of the condensing optical system is installed in parallel with the screen 18 and the bottom surface 118, the screen of the illumination light source system 123 is not shortened. The effect that the image display apparatus 116 which can respond | correspond to various utilization forms by suppressing the height of the lower part 117 can be acquired.

  Further, according to the seventeenth embodiment, the optical axis 130B of the main part of the condensing optical system is made parallel to the screen 18, and the position of the illuminator 11B of the illumination light source system 123B in the ψ axis direction is ψ of the relay lens 126B. Since the optical axis 130B is tilted within a specified value of the tilt angle of the illumination light source system 123B so as to be higher than the position in the axial direction, the height of the screen lower portion 117 is increased without shortening the life of the illumination light source system 123B. The effect that the image display apparatus 116 which can respond | correspond to various utilization forms can be comprised can be acquired.

  Furthermore, according to the seventeenth embodiment, the adjustment base 132 for installing the condensing optical system is provided, and the accommodation hole 133 for accommodating the third optical path bending reflector 128 is provided in the adjustment base 132. The effect that the image display apparatus in which the height of the screen lower part 117 is further suppressed can be obtained is obtained.

  Furthermore, according to the seventeenth embodiment, at least one of the second optical path bending reflector 127 and the third optical path bending reflector 128 is a curved mirror. The degree of freedom can be given to the control, and various optical performance can be improved.

  63A is cut in half, one image display device 116 has two spaces S that are symmetrical to each other, and the condensing optical system is connected to one of the light condensing optical systems. While arranging in the space S, other components such as a power source may be arranged in the other space S.

  Further, when a transmission type spatial light modulation element such as a liquid crystal is applied to this image display device, illumination with the optical axis 130 shared without using the second and third optical path bending reflectors 127 and 128. A condensing optical system from the light source system 123 to the field lens 129 is disposed in the space S, and the optical axis 130 is made substantially parallel to the ξ-ζ plane in accordance with FIGS. What is necessary is just to make it inject light.

  Further, a known TIR prism (total reflection prism) that mediates the light from the third optical path bending reflector 128 to the micromirror device 14 and the light from the micromirror device 14 to the refractive optical lens 58 is provided. Thus, the seventeenth embodiment can be applied to a telecentric projection optical system in which the entrance pupil position of the refractive optical lens 58 is apparently at an infinite point.

Embodiment 18 FIG.
In the fourth embodiment, the refractive optical lens injection-molded with plastic synthetic resin has been described. However, the convex mirror (projection optical means, reflecting portion) of each embodiment may be manufactured with plastic synthetic resin. As in the case of the optical lens, it is possible to easily form the shape such as an aspherical surface and to achieve mass production at low cost.

  Now, when a convex mirror to be applied to an image display device is made of a synthetic resin, a countermeasure against temperature change under the usage environment of the image display device is one point. This is because the optical performance of the image display device deteriorates when the aspherical shape of the convex mirror is deformed or the optical axis shift occurs due to thermal expansion / contraction caused by temperature change. In the following description of the eighteenth embodiment, a convex mirror with a countermeasure against temperature change will be described.

70 is a diagram showing a configuration of a convex mirror applied to an image display apparatus according to Embodiment 18 of the present invention. FIGS. 70 (a) and 70 (b) are a front view and a side view, respectively.
In FIG. 70, reference numeral 134 denotes a synthetic resin convex mirror (projection optical means, reflecting portion), which is shown in each embodiment. Reference numeral 135 denotes an optical axis of the convex mirror 134. The convex mirror 134 has a shape obtained by cutting a non-reflective portion that does not project light (optical image signal) onto the screen from the rotationally symmetric aspherical convex mirror 134O around the optical axis 135 (FIG. 70 (a), The thickness from the front surface 134F to the rear surface 134R is made equal (see FIG. 70 (b), the fifteenth embodiment).

  When the non-reflective portion is cut out, the first screw retaining portion 136, the second screw retaining portion 137, and the third screw retaining portion 138 having the screw holes 136H, 137H, and 138H, respectively, are provided on the convex mirror 134. In addition, the first to third screw retaining portions 136 to 138 are threaded as described below to hold the convex mirror 134 in the image display device. In order to minimize the distortion of the reflecting surface of the convex mirror 134, it is desirable that the screw retaining portions 136 to 138 and the screw holes 136H to 138H be formed simultaneously with the convex mirror 134.

  The first screw retaining portion 136 is provided in the vicinity of the optical axis 135. That is, in the convex mirror 134 that looks rectangular in the front view as viewed from the direction of the optical axis 135 (FIG. 70A), the convex mirror vertex 135P of the front surface 134F and the optical axis 135 (marked with X in FIG. 70A). The first screw retaining portion 136 is positioned so that the eccentric distance from the optical axis 135 to the center of the screw hole 136H is shortest on the lower side on the nearest lower side. The allowable range of the eccentric distance will be described later.

  The first screw retaining portion 136 is perpendicular to the optical axis 135 of the convex mirror 134 by the convex mirror attachment mechanism (first reflection portion attachment mechanism) 140 fixed to the image display device, the taper screw 139, the washer 139W, and the nut 139N. The in-plane position is pivotally fixed to the mounting surface of the convex mirror mounting mechanism 140 (in English, pivot). By pivot-fixing, all the degrees of freedom of the convex mirror 134 are fixed except for the rotational movement about the insertion direction of the taper screw 139 into the screw hole 136H.

  For this pivot fixation, the shape of the hole (taper shape) is determined in accordance with the taper portion of the taper screw 139 up to the screw hole 136H of the convex mirror mounting mechanism 140 and the first screw retaining portion 136. After passing through the convex mirror mounting mechanism 140, it passes through the screw hole 136H and is tightened using, for example, a washer 139W and a nut 139N. By making the convex mirror mounting mechanism 140 and the screw hole 136H of the first screw retaining portion 136 into a tapered shape, the pivot can be fixed securely. When the screwing is completed, the taper portion of the taper screw 139 stays inside the convex mirror mounting mechanism 140, and the portion protruding from the convex mirror mounting mechanism 140 is fixed by a washer 139W and a nut 139N.

  In contrast to the first screw retaining portion 136, the second screw retaining portion 137 and the third screw retaining portion 138 are provided on the left side and the right side of the front view of the convex mirror 134 in FIG. Thus, the area of the isosceles triangle formed by connecting the center point of the second screw retaining portion 137, the center point of the third screw retaining portion 138, and the convex mirror vertex 135P with a line segment is made as large as possible.

  The second screw retaining portion 137 and the third screw retaining portion 138 are connected to the mounting surface of the convex mirror mounting mechanism 142 (second reflecting portion mounting mechanism and third reflecting portion mounting mechanism, respectively) 142 of the image display device. The slide screws 141 are used to hold the slides. The slide holding means that when the convex mirror 134 is thermally expanded and contracted, the second screw retaining portion 137 and the third screw retaining portion 138 are displaced along the mounting surface of the convex mirror mounting mechanism 142, respectively.

  In order to hold the slide, the screw hole 137H of the second screw retaining portion 137 and the screw hole 138H of the third screw retaining portion 138 are both made larger in diameter than the screw diameter of the straight screw 141. The mounting surface of the mounting mechanism 142 has a large area and has an inclination in the sliding direction, and is held in contact with the second screw retaining portion 137 and the third screw retaining portion 138. The straight screw 141 passes through the convex mirror mounting mechanism 142 and then passes through the screw hole 137H (138H). For example, when the convex mirror 134 is thermally expanded / contracted using the washer 141W or the nut 141N, the straight thread 141 of the convex mirror mounting mechanism 142 is used. It can be tightened gently with enough strength to slide along the mounting surface. In addition, a lubricant layer made of a lubricant is provided between the attachment surface of the convex mirror attachment mechanism 142 and the screw retaining portion 137 (136) as necessary so that the above-mentioned slide is caused smoothly.

  As described above, the first to third screw retaining portions 136 to 138 hold the convex mirror 134 on the image display device with three points, and this embodiment is designed to take measures against temperature changes of the convex mirror 134. This is a feature of Form 18. Next, the operation of the convex mirror 134 with respect to the temperature change will be described.

  FIG. 71 is a diagram showing a state in which the convex mirror 134 at room temperature thermally expands due to a temperature change. The same reference numerals as those in FIG. 70 denote the same components. In FIG. 71, a convex mirror 134 at room temperature and a convex mirror 134 'that has been heated from room temperature and thermally expanded are overlapped. Symbols without the symbol “′ (dash)” indicate components of the convex mirror 134 at room temperature, and symbols with the symbol “′ (dash)” indicate components of the thermal expansion convex mirror 134.

  In FIG. 71A, the first screw retaining portion 136 is fixed at the in-plane position with respect to the optical axis 135, so that it becomes a fixed point for stress deformation, and the stress of shape change due to thermal expansion is the other part of the convex mirror 134. It starts to take. At this time, since the first screw retaining portion 136 is provided in the vicinity of the optical axis 135 with a predetermined eccentric distance, the deviation of the optical axis 135 can be minimized.

  The stress generated when the temperature changes to thermal expansion due to a temperature change is converted into a shift between the second screw retaining portion 137 and the third screw retaining portion 138 held by the slide. FIG. 71 (b) is an enlarged view of the third screw retaining portion 138 (broken line) at room temperature and the third screw retaining portion 138 '(solid line) during maximum thermal expansion.

  As described above, the screw hole 138H (137H) of the third screw retaining portion 138 has a larger diameter compared to the screw diameter of the straight screw 141. Therefore, the third screw retaining portion 138 is a convex mirror. The front surface 134F of the convex mirror 134 slides along the mounting surface of the mounting mechanism 142 and changes in a similar manner while maintaining its shape at room temperature and after thermal expansion, and the optical performance of the image display device with respect to temperature changes. Can be prevented. Of course, the same can be considered when heat shrinkage occurs.

  As can be seen from FIG. 71 (c), the relative size of the hole diameter of the screw hole 138H and the screw diameter of the straight screw 141 is determined based on the temperature specification of the image display device. It may be determined from 'and the shift positional relationship (deviation amount) of the screw hole 138H' 'at the time of the minimum contraction. The relative size between the screw hole 137H and the screw diameter of the straight screw 141 can be determined in the same manner.

  The eccentric distance of the first screw retaining portion 136 from the convex mirror vertex 135P can be determined as follows, for example. FIG. 72 is a diagram for explaining the deviation Δ (θ) of the convex mirror vertex 135P when the convex mirror 134 rotates about the first screw retaining portion 136 having the eccentric distance EXC. The same reference numerals as those in FIG. 70 denote the same components.

  Since the convex mirror 134 is pivotally fixed by the first screw retaining portion 136, the position of the convex mirror vertex 135P of the convex mirror 134 is also determined by the first screw retaining portion 136. Accordingly, in the assembly process of the image display device, the deviation Δ (θ) of the convex mirror vertex 135P occurs when the first screw retaining portion 136 is pivot-fixed.

  That is, as shown in FIG. 72 (a), the deviation Δ of the convex mirror vertex 135P in the vertical direction when the convex mirror 134 is rotated by an angle θ around the screw hole 136H eccentric from the convex mirror vertex 135P by the eccentric distance EXC. (Θ) is caused by an assembly error. Considering this, the eccentric distance EXC of the first screw retaining portion 136 can be determined so that the deviation Δ (θ) is within the allowable range from the size of the convex mirror 134 and the adjustable range of the rotation error θ in the assembly process. It ’s fine.

  Now, in FIG. 72A, the deviation Δ (θ) of the optical axis 135 can be obtained as Δ (θ) = EXC · [1−cos (θ · π / 180)]. Based on this equation, for example, the relationship between the rotation error θ and the deviation Δ (θ) when the eccentric distance EXC = 20 mm is shown in FIG. The horizontal axis and the vertical axis represent the rotation error θ and the deviation Δ (θ), respectively.

  As an example, the adjustable range of the rotation error θ is 2 deg. , When the maximum allowable value of the deviation Δ (θ) is 0.1 mm, θ = 2 deg. Since Δ (θ) <0.02 mm, the convex mirror 134 manufactured by setting the first screw retaining portion 136 to the eccentric distance EXC = 20 mm has a sufficient assembly margin of 5 times or more.

  It should be noted that the eccentric distance EXC = 0 mm, that is, the center of the screw hole 136H may coincide with the convex mirror vertex 135P. Naturally, in this case, since the deviation Δ (θ) of the convex mirror vertex 135P does not occur, the convex mirror 134 can be held in a more ideal state.

  Further, in FIG. 70, the screw fastening is performed so that the first to third screw retaining portions 136 to 138 are closer to the rear surface 134R than the convex mirror mounting mechanisms 140 and 142. The reason is that the molding is performed with high accuracy. This is because the shape and position of the front surface 134F are maintained by the convex mirror mounting mechanisms 140 and 142 so that the stress of the convex mirror 134 caused by the temperature change becomes the shape change of the rear surface 134R. Thereby, the shape change of the front surface 134F can be suppressed.

The convex mirror 134 with countermeasures against temperature change has been described above, but the shape is not limited to that shown in FIG. 70. For example, a convex mirror 134 as shown in FIG. 73 can be considered.
FIG. 73 is a diagram showing a variation of the configuration of the convex mirror 134 to which a measure against temperature change is taken, and both are front views. The same reference numerals as those in FIG. 70 denote the same or corresponding configurations.

  In FIG. 73A, a concave portion 144 is formed in place of the first screw retaining portion 136 so that the curved surface of the columnar support 145 is fitted into the concave portion 144. At this time, since it is necessary to press the concave portion 144 against the cylindrical support body 145, springs 143 for pulling the convex mirror 134 vertically downward are provided on the left and right sides of the concave portion 144.

  In FIG. 73 (b), a convex portion 146 is formed in place of the first screw retaining portion 136, and the convex portion 146 is fitted into the V groove portion of the V groove support 147. Similarly to FIG. 70A, since the convex portion 146 needs to be pressed against the V-groove support 147, two springs 143 that pull the convex mirror 134 vertically downward are provided on the left and right sides of the convex portion 146. In this case, if the convex mirror vertex 135P is positioned at the center of the arc-shaped convex portion 146, the eccentric distance described with reference to FIG. 72 becomes zero, and the convex mirror 134 can be held in a more ideal state. .

  Further, as shown in FIG. 73 (c), a second screw retaining portion 137 and a third screw retaining portion 138 may be provided on the upper side facing one side where the first screw retaining portion 136 is provided. The effect similar to that in the case of FIG. 70 is obtained.

  Furthermore, since the case where the top and bottom of the image display device is reversed (see Embodiment 17) is also assumed, at this time, as shown in the front view of FIG. One end of the two springs 143 is fixed to the left and right spring retaining portions 146A and 146B of the portion 136, respectively, and the other end of the spring 143 is fixed to one point Ps, and the convex mirror 134 is pulled by the spring 143. good.

  At this time, the position where the spring 143 is fixed at one point is higher than that of the first screw retaining portion 136 so that the pulling force of the spring 143 against the convex mirror 134 is balanced in the left and right directions. By doing in this way, the stress concentrated on the first screw retaining portion 136 can be distributed to the spring 143, and the reliability of the first screw retaining portion 136 can be improved.

  As described above, according to the eighteenth embodiment, since the convex mirror is manufactured with the plastic synthetic resin, the shape can be easily formed, and the effect of being mass-produced at a low cost can be obtained.

  Further, according to the eighteenth embodiment, the first screw retaining portion 136 that is provided in the vicinity of the convex mirror vertex 135P near the front lower side of the convex mirror 134 at a predetermined eccentric distance EXC and is pivotally fixed, and the front left side of the convex mirror 134 The second screw retaining portion 137 that is slid and held on the front surface of the convex mirror 134 and the third screw retaining portion 138 that is slidably retained on the front right side of the convex mirror 134 are provided on the convex mirror 134. Due to the heat shrinkage, the deformation of the convex mirror 134 and the deviation of the convex mirror apex 135P can be suppressed, and the optical performance of the image display apparatus can be prevented from deteriorating.

  Further, according to the eighteenth embodiment, the convex mirror mounting mechanism 140 and the first screw retaining portion 136 are threaded by the taper screw 139 and have a tapered hole that matches the tapered portion of the taper screw 139. As a result, the effect that the pivot can be securely fixed is obtained.

  Furthermore, according to the eighteenth embodiment, the concave portion 144 provided in the vicinity of the convex mirror apex 135P at a predetermined eccentric distance EXC on the lower front side of the convex mirror 134, the cylindrical support 145 that fits the curved surface into the concave portion 144, the concave portion Convex mirror 134 includes two springs 143 each having one end fixed to the left and right of 144 and having a tensile force, a second screw retaining portion 137 that is slid and held, and a third screw retaining portion 138 that is slid and held. Therefore, the thermal expansion and contraction caused by the temperature change can suppress the deformation of the convex mirror 134 and the deviation of the optical axis 135, thereby preventing the optical performance of the image display apparatus from deteriorating. Is obtained.

  Furthermore, according to the eighteenth embodiment, an arc-shaped convex portion 146 provided near the convex mirror vertex 135P near the front lower side of the convex mirror 134, a V-groove support 147 that fits the convex portion 146 into the V-groove, A convex mirror includes two springs 143 each having one end fixed to the left and right sides of the portion 146 and having a tensile force, a second screw retaining portion 137 that is slid and held, and a third screw retaining portion 138 that is slid and held. 134, the thermal expansion and contraction caused by the temperature change can suppress the deformation of the convex mirror 134 and the deviation of the optical axis 135, thereby preventing the optical performance of the image display device from deteriorating. An effect is obtained.

  Further, according to the eighteenth embodiment, one end of each of the first screw retaining portions 136 is fixed to the left and right sides, and the other end is fixed at a common point, and two springs 143 having a tensile force are provided. Thus, when the image display device is used upside down, the stress concentrated on the first screw retaining portion 136 can be distributed to the spring 143, and the first screw retaining portion 136 can be dispersed. Reliability can be improved.

  Furthermore, according to the eighteenth embodiment, the front surface 134F side, which is the reflection surface of the convex mirror 134, of the screw retaining portions 136, 137, and 138 is held in contact with the convex mirror mounting mechanisms 140 and 142. Therefore, the effect that the reflective surface of the convex mirror 134 can be arrange | positioned accurately is acquired.

  In the above description, the convex mirror 134 has a rotationally symmetric shape around the optical axis 135. However, the eighteenth embodiment can also be applied to non-rotationally symmetric synthetic resin components.

  Further, the second screw retaining portion 137 and the third screw retaining portion 138 are not limited to one each, and two or more each may be provided.

Embodiment 19. FIG.
Following the eighteenth embodiment, an image display apparatus in which this nineteenth embodiment also takes measures against temperature changes will be described.
FIG. 75 is a diagram showing the configuration of an image display apparatus according to Embodiment 19 of the present invention, and illustration of the configuration after the illumination light source system and convex mirror is omitted.

  In FIG. 75, 148 is a micromirror device (transmission means, image information providing unit), 149 is a refractive optical lens of each embodiment, 150 is an optical axis of the refractive optical lens 149, 151 is a micromirror device 148 or refractive optical lens. 149 is an optical base (holding mechanism) on which an optical system such as 149 is installed. The optical base 151 corresponds to the holding mechanism 74 (see Embodiment 10) shown in FIG. 43, and integrally holds the refractive optical lens 149 and an optical path bending reflector / convex mirror (not shown). A mirror device 148 is also held.

  Reference numerals 152 and 153 denote two slide support columns which are fixed to the optical base 151 and support the refractive optical lens 149 by sliding. The refractive optical lens 149 can slide on the slide support columns 152 and 153 in the direction of the optical axis 150.

  154 is a mounting plate fixed on the optical base 151, 155 is a mounting plate fixed to the lower part of the refractive optical lens 149, and 156 has a length in the direction of the optical axis 150 by a DC control voltage applied from a power source (not shown). It is a changing piezoelectric element. Each of the mounting plates 154 and 155 is between the slide support column 152 and the slide support column 153, and holds the piezoelectric element 156 in contact with each other so as to sandwich the piezoelectric element 156 between the surfaces facing each other.

  The light (optical image signal) emitted from the micromirror device 148 sequentially proceeds to a convex mirror (not shown), a plane mirror, and a screen through the refractive optical lens 149 as shown in each embodiment. At this time, when the focus of the image displayed on the screen is initially adjusted at room temperature, for example, the focus of the image may be distorted due to the temperature change in the usage environment of the image display device.

  This out-of-focus occurs due to differences in the temperature distribution and linear expansion coefficient of each lens group in the refractive optical lens 149 and the distance between the lenses, and the optical base 151 and each optical system component on the optical base 151. This is because the degree of thermal expansion and contraction in the direction of the optical axis 150 is different, and the relative positional relationship between the components of the optical system is shifted. What is particularly problematic is the change in the length L0 in the direction of the optical axis 150 from the micromirror device 148 to the refractive optical lens 149, and it is understood from the results of numerical analysis and the like that it has a great influence on the focus deviation. ing. This is because the value of L0 at which the focus is optimum changes due to the temperature change of the lens itself, the optimum value L0 becomes L0A, and the physical distance L0 changes to L0B due to the physical change of the L0 value due to temperature change. There are two factors. Here, even if the temperature changes, if the relationship L0A = L0B is preserved, the focus will not be out of order. However, when L0A ≠ L0B, a focus error occurs.

  In order to compensate for this change in length L0B-L0A, in FIG. 75, a piezoelectric element 156 whose length in the direction of the optical axis 150 can be adjusted by a control voltage is provided. That is, the initial focus adjustment is performed in a state where the initial offset of the control voltage is applied to the piezoelectric element 156. Then, the control voltage applied to the piezoelectric element 156 is increased / decreased according to the temperature change of the usage environment for the image display device.

  Thus, when the length of the piezoelectric element 156 in the direction of the optical axis 150 is changed and the distance between the mounting plates 154 and 155 held in contact with the piezoelectric element 156 is changed, the refractive optical lens is placed on the slide support columns 152 and 153. 149 slides along the optical axis 150.

  For example, when the length L0B-L0A becomes longer than the initial adjustment state due to a temperature change, the length of the piezoelectric element 156 is decreased by reducing the control voltage. Thereby, the refractive optical lens 149 slides on the slide support columns 152 and 153 and approaches the micromirror device 148 along the direction of the optical axis 150, so that the length L0 affected by the temperature change is brought into the initial adjustment state. Can be returned.

  Conversely, when the length L0B-L0A becomes shorter, the control voltage is increased to increase the length of the piezoelectric element 156. Accordingly, the refractive optical lens 149 slides on the slide support columns 152 and 153, moves away from the micromirror device 148 along the direction of the optical axis 150, and returns the length L0 affected by the temperature change to the initial adjustment state. Can do.

  As described above, in the configuration shown in FIG. 75, the change in the length L0 that has a great influence on the focus deviation can be compensated by adjusting the control voltage to the piezoelectric element 156, which is caused by the temperature change. You can adjust the focus deviation.

  Further, a configuration as shown in FIG. 76 is also conceivable as a countermeasure against temperature change against a focus error. FIG. 76 shows a structure of an image display device according to the nineteenth embodiment of the present invention. The same reference numerals as those in FIG. 75 denote the same components, and the illustration of the illumination light source system and the configuration subsequent to the convex mirror is omitted.

  In FIG. 76, reference numeral 157 denotes a gear support column fixed on the optical base 151. The gear mechanism 157G including a motor or the like precisely moves the refractive optical lens 149 in the direction of the optical axis 150 with less play in the direction of the optical axis 150. To move to. Reference numerals 158 and 159 denote temperature sensors. The temperature sensor 158 senses the lens barrel temperature T1 of the refractive optical lens 149, and the temperature sensor 159 senses the temperature T2 of the optical base 151, respectively.

  Reference numeral 160 denotes a heating / cooling device for heating / cooling the optical base 151, and a Peltier element is a typical example. A control unit 161 such as a CPU performs feedback control of the gear mechanism 157G and the heating / cooling device 160 in accordance with the temperatures T1 and T2.

  75, the length L0B-L0A is adjusted by the piezoelectric element 156. In FIG. 76, the refractive optical lens 149 is moved in the direction of the optical axis 150 by the gear mechanism 157G to adjust the length L0B-L0A. Yes. Even if it does in this way, the effect similar to the case of FIG. 75 will be acquired.

  Also, the characteristic point in FIG. 76 is that the temperature sensors 158 and 159 sense the temperatures T1 and T2 of the refractive optical lens 149 and the optical base 151 in real time, respectively, and the control unit 161 performs gearing according to these temperatures T1 and T2. The mechanism 157G and the heating / cooling device 160 are feedback-controlled.

  Now, the linear expansion coefficient of the barrel of the refractive optical lens 149 and the linear expansion coefficient of the optical base 151 are ρ1 and ρ2, respectively, and the refractive optical lens 149 in the direction of the optical axis 150 from the light incident end to the position of the gear support column 157 is used. Is L1 (L0 + L1 = L2), and the temperatures of the refractive optical lens 149 and the optical base 151 during initial focus adjustment are both T0.

  When the image display device is placed in a use environment and a temperature gradient is generated therein, and the length L0 changes to L0B = L0 + ΔL0, the temperature sensors 158 and 159 are connected to the refractive optical lens 149 and the optical base 151. It is assumed that the temperatures are sensed as T1 and T2 (T1 ≠ T2), respectively. At this time, the change ΔL0B can be obtained as ΔL0B = L2 · ρ2 · (T2−T0) −L1 · ρ1 · (T1−T0). In addition, a change amount ΔL0B of the value of L0 that optimizes the focus with respect to the lens barrel temperature T1 is stored in advance in the control unit 161.

  The control unit 161 calculates the physical change ΔL0B of the length L0, and the control unit 161 adjusts the gear mechanism 157G to set the length of L0 so that the optical focus movement amount ΔL0B−ΔL0A is zero. To compensate. By doing so, the refractive optical lens 149 moves in the direction of the optical axis 150 by the gear mechanism 157G so as to cancel the optical focus movement amount ΔL0B-ΔL0A (focus compensation amount). The focus of the image displayed on the screen (not shown) can be maintained without depending on the temperature change. Of course, as with the piezoelectric element 156, the gear mechanism 157G may be operated with a control voltage.

  Further, when the temperature T1, T2 is given from the temperature sensors 158, 159, the control unit 161 adjusts the optical base 151 by the heating / cooling device 160 intentionally instead of adjusting the length of L0 by adjusting the gear mechanism 157G. The length of L2 may be controlled by heating / cooling and utilizing the thermal expansion / contraction of the optical base 151. By doing so, it becomes possible to suppress the temperature gradient that caused the focus error, and the focus of the image displayed on the screen (not shown) is maintained without depending on the temperature change under the use environment. can do.

  Note that the temperature sensor 158, 159, the control unit 161, and the gear mechanism 157G and the temperature sensor 158, 159, the control unit 161, and the heating / cooling device 160 may take only one of them. It can be used together.

  Further, the quantity of the temperature sensors 158 and 159 is not particularly limited. Similarly, the quantity of the heating and cooling device 160 is not limited, and the positions of the temperature sensors 158 and 159 and the heating and cooling device 160 are not limited.

  Furthermore, it is conceivable that the refractive optical lens 149 is heated and cooled by the superheater 160 as long as it does not cause any particular problem in terms of the performance of the image display device.

  Further, the temperature sensors 158 and 159 and the control unit 161 shown in FIG. 76 may be applied to the piezoelectric element 156 shown in FIG.

  Furthermore, since the temperatures T1 and T2 sensed by the temperature sensors 158 and 159 do not necessarily reflect the focus of the image, a learning function is provided in the control unit 161, and countermeasures against temperature changes are taken with this learning function. May be.

That is, the adjuster performs initial focus adjustment of the image display device under a certain environmental temperature T3, and the length [L0] _T3 at this time is stored in the control unit 161. Subsequently, in the same manner, the initial focus adjustment is performed even under the environmental temperature T4 (≠ T3), and the length [L0] _T4 at this time is also stored in the control unit 161.

Accordingly, the control unit 161 derives an interpolation relational expression by linearly interpolating these two points from the two focus adjustment points (T3, [L0] _T3 ) and (T4, [L0] _T4 ). The control unit 161 senses an arbitrary environmental temperature Tx of the image display device placed in the actual environment with a temperature sensor, obtains an optimum length [L0] _Tx for the environmental temperature Tx from the interpolation relational expression, The length L0 (focus compensation amount) is compensated by the element 156 and the gear mechanism 157G.
In addition, if the number of learning is n times or more (3 or more focus adjustment points) and an interpolation relational expression is introduced from the relationship between the n values of the optimum length corresponding to each temperature and the temperature, More accurate focus compensation is possible.

  In the case of this learning control method, the relationship between the environmental temperature and the focus is correlated one-to-one with the eyes of the adjuster, and the control unit 161 learns the result, so that more accurate focus adjustment can be performed. . In this case, the temperature sensor is provided in the image display device so as to be able to sense the environmental temperature.

  Further, for the same reason as the learning control method described above, instead of the temperatures T1 and T2 that do not necessarily reflect the focus deviation, the focus of the image displayed on the image display device is directly detected and feedback control is performed. good.

FIG. 77 shows a structure of an image display device according to the nineteenth embodiment of the present invention. 75 and 76 are the same or corresponding components.
In FIG. 77, 162 is a convex mirror (projection optical means, reflector) of each embodiment, 163 is a plane mirror (Embodiment 1), and 164 is a screen (display means). The display image on the screen 164 is overscanned and divided into an image display area 165 and a non-image display area 166. For example, if the image is cut by 12 dots from the top, bottom, left, and right of the 1024 × 768 XGA standard, the image display area 165 becomes 1000 × 744, and the non-image display area 166 becomes a 12-dot wide band with diagonal lines.

  Reference numeral 167 denotes a small reflecting mirror, and reference numeral 168 denotes a CCD element. The small reflecting mirror 167 reflects the light projected from the plane mirror 163 to the non-image display area 166, and the CCD element 168 receives the light reflected by the small reflecting mirror 167, and the focus information obtained from this light is sent to the control unit. 161 to output.

  Here, the small mirror of the micromirror device 148 is controlled so that, for example, light corresponding to a one-dot display image is always received by the CCD element 168. Note that the light receiving surface of the CCD element 168 and the image forming surface of the screen 164 are disposed at the same optical path length with respect to the projection optical system including the refractive optical lens 149 and the convex mirror 162.

Next, the operation will be described.
Most of the light from the micromirror device 148 sequentially proceeds to the refractive optical lens 149, the convex mirror 162, the plane mirror 163, and the screen 164, and displays an image in the image display area 165. The light of the one-dot display image incident on the non-image display area 166 of the screen 164 in the same order is reflected by the small reflecting mirror 167 and incident on the CCD element 168.

The CCD element 168 refers to all pixels in the CCD element, obtains the focus information of the image displayed in the image display area 165 from the light of the one-dot display image, and outputs it to the control unit 161 as the first focus information. The control unit 161 analyzes the first focus information and feedback-controls the refractive optical lens 149 having the configuration shown in FIGS. 75 and 76 to adjust the focus of the image.
Generally, when focus adjustment is performed, the position on the screen where the focus is best may be slightly moved due to optical non-uniformity. For this reason, by referring to all the pixels in the CCD element 168 every time focus adjustment is performed, it is possible to compensate for the shift of the focus position on the CCD element 168.

Most of the light from the refractive optical lens 149 that is feedback-controlled displays an image in the image display area 165. The light of the 1-dot display image toward the non-image display area 166 is detected as the second focus information by the small reflecting mirror 167 and the CCD element 168 and used for feedback control of the control unit 161 with respect to the refractive optical lens 149. Thereafter, the same operation is repeated after the third time.
As described above, the focus information is detected by the CCD element 168 from the light of the one-dot display image incident on the non-image display area 166, so that the focus error can be directly detected without using secondary information such as temperature. The reflected focus can be adjusted.

When focus adjustment is performed on the projection optical system, the projection optical system may move slightly mechanically, or the distortion characteristics may change slightly, and the 1-dot display image position on the CCD element 168 may slightly move. Even when the entire image display apparatus is moved, the projection optical system may be mechanically deformed by a minute amount due to a change in the external stress applied to the image display apparatus, and the 1-dot display image position may slightly move.
In any case, the CCD element 168 is sufficiently large with respect to the moving range of the image (with a size that satisfies the image moving amount and the measurement area). It is set so as not to protrude from the CCD element 168. In this way, if the one-dot display image position and its peripheral information are measured for each measurement, accurate focus adjustment can be performed without affecting the measurement result even if image movement (displacement) occurs. become able to.

In the above operation, a method for analyzing focus information by the control unit 161 will be described a little more.
FIG. 78 is a diagram showing a focus information analysis method of the control unit 161, and illustrates three methods of FIGS. 78 (a) to 78 (c). The horizontal axis is the position coordinate of the light receiving surface of the CCD element 168, and is actually a two-dimensional coordinate. The vertical axis represents the light intensity.

  78 (a) to 78 (c), Cm and Cm + 1 are focus information of the m-th and m + 1-th (m = 1, 2,...), Respectively, and indicate the light intensity distribution characteristics. Specifically, Cm and Cm + 1 are electrical signals obtained from the respective unit light receiving elements of the two-dimensional array of CCD elements 168, and are profiles proportional to the illuminance distribution of the light of the one-dot display image incident on the CCD element 168. Have

  In addition, Peakm and Peakm + 1 in FIG. 78A are the intensity peak values of the focus information Cm and Cm + 1, respectively, and FWHMm and FWHMm + 1 in FIG. 78B are the full width at half maximum (Full Width Half Maximum) of the focus information Cm and Cm + 1, respectively. .

  Furthermore, GRADm and GRADm + 1 in FIG. 78 (c) are the magnitudes of the slopes of the shoulders converted from the peak values in the focus information Cm and Cm + 1, respectively. For example, the focus information from which 10% and 90% of the peak value intensity are obtained. It represents the slope of a straight line connecting specific points on Cm and Cm + 1. The slope of the shoulder is the slope of a straight line connecting two points at which the peak values α and β% (0% <α, β <100%, α ≠ β) are obtained.

  When the analysis method of FIG. 78 (a) is followed, the control unit 161 adjusts the refractive optical lens 149 so that the peak value Peakm + 1 of the m + 1th focus information is larger than the peak value Peakm obtained from the mth focus information. Feedback control.

In the case of FIG. 78B, in the case of FIG. 78C, the full width at half maximum FWHMm + 1 of the m + 1th focus information is smaller than the full width at half maximum FWHMm obtained from the mth focus information. The control unit 161 feedback-controls the refractive optical lens 149 so that the shoulder inclination GRADm + 1 of the m + 1th focus information is larger than the shoulder inclination GRADm obtained from the mth focus information.
It should be noted that the width giving a predetermined level in the focus information (a width of the predetermined level) is minimized, such as a width other than the half-full width of the focus information, for example, a width of 1/10 intensity 1 / e ^2. Of course.

  In any of the cases shown in FIGS. 78A to 78C, the focus of the image displayed in the image display area 165 can be adjusted from the focus information obtained by the CCD element 168.

  In FIG. 77A, the small reflecting mirror 167 and the CCD element 168 are arranged in the non-image display area 166. However, as shown in FIG. 77B, the housing of the image display device (at the edge of the image display area 165). In the case of limiting (shown by a two-dot broken line), the small reflector 167 shows a particularly effective effect. In other words, the focus information can be detected by arranging the small reflecting mirror 167 and the CCD element 168 inside the casing without causing vignetting of light projected on the image display area 165 under the limitation of the casing.

  Regarding the arrangement positions of the small reflecting mirror 167 and the CCD element 168, they are arranged so as to satisfy the following conditions.

The distance between the small reflecting mirror 167 and the CCD element 168 in which the small reflecting mirror 167 is arranged away from the screen 164 is equal to the optical path length from the small reflecting mirror 167 to the screen 164.

  Of course, as shown in FIG. 79, only the CCD element 168 may be arranged at an arbitrary position in the non-image display area 166 to directly detect the illuminance distribution of light equivalent to one dot.

  Further, the display pattern for focus adjustment may be a display image such as a line shape or a cross line other than the one-dot display image.

Here, one numerical example related to temperature change countermeasures will be described.
In the above description, the entire refractive optical lens 149 is moved to adjust the focus with respect to the temperature change. However, the nineteenth embodiment is not limited to this. As described in each part of this specification, since the refractive optical lens 149 includes a plurality of lenses, a part of all the lens groups constituting the refractive optical lens 149 or the convex mirror 162 is used for focus adjustment. May be moved by a method similar to that shown in FIGS. When the convex mirror 162 is moved, the gear mechanism 157G may be driven and controlled using the gear support column 157 provided with the gear mechanism 157G for holding the convex mirror.

For example, the configuration of the image display apparatus shown in Numerical Example 14A (FIG. 53) is shown again in FIG.
Of all the lens groups constituting the refractive optical lens 149, a lens 149A closest to the convex mirror (not shown in FIG. 80), a lens 149B closest to the convex mirror next to the lens 149A, and a lens 149C closest to the convex mirror next to the lens 149B. When the three lenses are moved in the direction of the optical axis 150, it is possible to compensate for the change in the distance L0 from the micromirror device 148 to the refractive optical lens 149 while minimizing the deterioration of the imaging performance. I know from the results.

As the last of the nineteenth embodiment, countermeasures for temperature change in the vertical direction of each component will be described.
As shown in FIG. 81, regarding the deviation in the vertical direction (normal direction of the optical base 151) that each component on the optical base (holding mechanism) 151 receives due to temperature change, for example, the slide support column 152 of the refractive optical lens 149. 153, and the fixed support column 169 for fixing and supporting the convex mirror 161 on the optical base, the product of the vertical height and the linear expansion coefficient of the slide support columns 152 and 153 and the fixed support column 169 is equalized. good.

  By doing in this way, the deviation in the vertical direction due to the temperature change is constant in any component, and the deviation of the optical axis 150 in the vertical direction can be prevented. In FIG. 81, the support pillars of the micromirror device 148 are not shown, but the product of the vertical height and the linear expansion coefficient is also equal to the other support pillars for the support pillars of the micromirror device 148. To do.

  As described above, according to the nineteenth embodiment, the two slide support columns 152 and 153 provided on the optical base 151 and slidably supporting all or part of the refractive optical lens 149 are provided. The mounting plates 154 and 155 and the mounting plates 154 and 155 are respectively fixed on the optical base 151 and the lower part of the whole or a part of the refractive optical lens 149 and located between the slide support columns 152 and 153. Since the piezoelectric element 156 that is held in contact so as to be sandwiched and whose length changes in the direction of the optical axis 150 by increasing or decreasing the control voltage is provided, it is possible to adjust the focus deviation caused by the temperature change. It is done.

  According to the nineteenth embodiment, the gear support is provided on the optical base 151 and moves the entire refractive optical lens 149 or a part of the lens group in the direction of the optical axis 150 by the gear mechanism 157G. Since the column 157 is provided, an effect of adjusting the focus deviation caused by the temperature change can be obtained.

  Further, according to the nineteenth embodiment, since the heating / cooling device 160 is provided in at least one of the optical base 151 and the refractive optical lens 149, the temperature gradient generated in the use environment is suppressed and the focus is reduced. The effect is that you can adjust the madness.

  Further, according to the nineteenth embodiment, the temperature sensor 158 for sensing the lens barrel temperature T1 of the refractive optical lens 149, the temperature sensor 159 for sensing the internal temperature T2 of the optical base 151, the lens barrel temperature T1 and the internal temperature. Since the optimal value or temperature difference ΔT of the length L0 is calculated from T2, and the control unit 161 that feedback-controls at least one of the piezoelectric element 156, the gear mechanism 157G, and the heating / cooling device 160 is provided. The effect of adjusting the focus error caused by the change is obtained.

Furthermore, according to the nineteenth embodiment, the temperature sensor for sensing the temperature under the usage environment, the length [L0] _T3 of the environmental temperature T3 in the initial focus adjustment, and the length [L0] of the environmental temperature T4 in the initial focus adjustment [ L0] The length L0 suitable for the temperature in the operating environment is calculated according to the linear interpolation formula obtained by linearly interpolating _T4, and the control unit 161 that feedback-controls the piezoelectric element 156 or the gear mechanism 157G is provided. There is an effect that more accurate focus adjustment can be performed by associating the relationship between the temperature and the focus one-to-one.

  Furthermore, according to the nineteenth embodiment, the CCD element 168 that detects focus information from the light incident on the non-image display area 166 of the screen 164, and the focus information obtained from the CCD element 168 are analyzed, and the piezoelectric element 156 is analyzed. Alternatively, since the gear mechanism 157G is provided with the control unit 161 that performs feedback control, the focus adjustment can be performed by directly reflecting the focus error without using secondary information such as temperature.

  Furthermore, according to the nineteenth embodiment, since the small reflecting mirror 167 that reflects the light incident on the non-image display area 166 to the CCD element 168 is provided, the housing is limited to the limit of the image display apparatus area 165. Even in such a case, it is possible to detect the focus information.

  Further, according to the nineteenth embodiment, the control unit 161 uses the intensity distribution characteristic profile of light incident on the CCD element 168 as focus information, and performs feedback control so as to make the peak value Peakm of the focus information as large as possible. The effect of adjusting the focus directly reflects the focus error.

  Furthermore, according to the nineteenth embodiment, the control unit 161 uses the intensity distribution characteristic profile of light incident on the CCD element 168 as focus information, and performs feedback control so as to make the full width at half maximum FWHMm of the focus information as small as possible. The effect of adjusting the focus directly reflects the focus error.

  Furthermore, according to the nineteenth embodiment, the control unit 161 uses the intensity distribution characteristic profile of the light incident on the CCD element 168 as focus information, and performs feedback control so as to increase the inclination GRADm of the shoulder of the focus information as much as possible. Since this is done, it is possible to adjust the focus directly reflecting the focus error.

  Further, according to the nineteenth embodiment, the slide support columns 152 and 153 of the refractive optical lens 149 and the fixed support column 169 of the convex mirror 161 are all made equal in product of the vertical height and the linear expansion coefficient. Thus, an effect that the deviation of the optical axis 150 in the vertical direction can be prevented is obtained.

  In the above description, the micro-mirror device has been described as the light spatial modulation element, but the same effect can be obtained by using another light spatial modulation element such as a transmissive or reflective liquid crystal.

Embodiment 20. FIG.
82 is a diagram showing a configuration of a convex mirror applied to an image display apparatus according to Embodiment 20 of the present invention. In FIG. 82, reference numeral 170 denotes a convex mirror (projection optical means, reflecting portion) of each embodiment, which is formed by cutting a non-reflective portion from a rotationally symmetric convex mirror 170O around the optical axis 171. A reflection convex portion 172 is provided in the vicinity of the optical axis 171 (non-projection front surface) of the front surface.

  The reflective convex portion 172 is obtained by making the high reflective surface 104H and the low reflective surface 104L of the convex mirror 104 shown in the fifteenth embodiment convex, or by making the entire surface a high reflective plane, and from the front surface of the convex mirror 170 Is also used when performing the alignment adjustment method of the image display device described below. Instead of the reflective convex portion 172, a reflective concave portion 173 shown in FIG. Naturally, the reflective recess 173 is formed by making the high reflection surface 104H and the low reflection surface 104L of the convex mirror 104 shown in the fifteenth embodiment concave or by making the entire surface a high reflection surface. The reflective surfaces of the reflective convex portion 172 and the reflective concave portion 173 are flat surfaces, and the normal line of the flat surface is parallel to the optical axis 171.

  FIG. 83 is a flowchart showing the alignment adjustment method according to the twentieth embodiment of the present invention. 84 to 88 are views showing a state in which the optical system components are sequentially arranged according to the steps of the alignment adjustment method of FIG. The same reference numerals as those in FIG. 82 denote the same components.

<Step ST1: Alignment adjustment of convex mirror with respect to jig screen>
In FIG. 84A, the parallel light beam emitted from the laser light source 174 and the normal line of the jig screen (jig display means) 176 are installed in parallel. The laser light source 174 emits a parallel light beam having a larger cross-sectional area than that of the reflection convex portion 172, and the parallel light beam enters the jig screen 176 through the beam splitter 175 vertically.

  A transmission hole (first transmission hole) 176H is provided around the optical axis of the jig screen 176 (FIG. 84B), and a part of the parallel light beam transmitted through the beam splitter 175 passes through the transmission hole 176H. The light passes through and proceeds to the reflective convex portion 172 of the convex mirror 170 installed on the optical base 177 (holding mechanism, see FIG. 43, Embodiment 10).

  In the convex mirror 170, the parallel convex light beam is reflected by the reflective convex portion 172, and is transmitted through the transmission hole 176H in the direction opposite to the parallel light beam in the forward path. The parallel light beam on the return path passes through the transmission hole 176H, enters the beam splitter 175, travels in a direction orthogonal to the parallel light beam from the laser light source 174, and is then divided into a quadrant detector 179 (FIG. c) is focused on the center of the detector).

  By adjusting the posture of the convex mirror 170 and equalizing each optical power detected by each of the four light receiving elements of the quadrant detector 179, the forward and backward paths of the parallel light flux between the transmission hole 176H and the reflective convex part 172 are obtained. The alignment (virtual optical axis) coincides with the optical axis 171 and the alignment adjustment of the convex mirror 170 with respect to the jig screen 176 is completed.

<Step ST2: Alignment Adjustment of Optical Path Bending Reflector with Convex Mirror>
From the state of FIG. 84A, the laser light source 174, the beam splitter 175, the condensing lens 178 and the quadrant detector 179 are moved while maintaining the mutual relationship, and the parallel light beams from the laser light source 174 and the beam splitter 175 are moved. Is aligned with the ideal optical axis 180 of the refractive optical lens. Then, the alignment adjustment of the optical path bending reflecting mirror 181 (refer to Embodiments 7 and 10 such as FIG. 23) 181 with respect to the convex mirror 170 is performed (FIG. 85).

  In FIG. 85, a parallel light beam having a cross-sectional area larger than that of the reflective convex portion 172 is emitted from the laser light source 174 through the beam splitter 175, and reflected to the reflective convex portion 172 by the optical path bending reflector 181 disposed at a predetermined position. To do. Since the reflection convex portion 172 has a smaller reflection surface than the incident parallel light beam, only a part of the parallel light beam is reflected to the optical path bending reflector 181.

  The parallel light flux from the reflection convex portion 172 is reflected by the optical path bending reflector 181, travels to the beam splitter 175, and is detected by the quadrant detector 179 through the condenser lens 178. As in the case of FIG. 84A, when the alignment adjustment (biaxial tilt angle adjustment) of the optical path bending reflecting mirror 181 with respect to the convex mirror 170 becomes ideal, the light receiving elements of the quadrant detector 179 detect the respective light receiving elements. Each optical power is equal.

  At this time, the parallel light flux between the reflection convex portion 172 and the beam splitter 175 has the forward path and the return path that coincide with each other via the optical path bending reflector 181, and the virtual optical axis of the ideal optical axis 180 of the refractive optical lens. Is produced by the light flux of the laser light source 174.

<Step ST3: Alignment Adjustment of Lens Holding Flange with Perforated Reflector>
With respect to the ideal optical axis 180 created in FIG. 85, a lens holding flange 182 for holding a refractive optical lens and a perforated reflector 183 attached in place of the refractive optical lens are installed on the lens holding flange 182 ( FIG. 86 (a)). The perforated reflecting mirror 183 has a transmission hole (second transmission hole) 183H through which light is transmitted (FIG. 86 (b)), and transmits the parallel light flux from the laser light source 174 and the beam splitter 175. It is like that. The periphery of the transmission hole 183H is a reflection surface.

  In FIG. 86 (a), the parallel light beam transmitted through the transmission hole 183H is directed from the optical path bending reflecting mirror 181 to the reflecting convex portion 172. The parallel light beam reflected by the reflecting convex portion 172 is reflected by the optical path bending reflecting mirror 181, passes through the transmission hole 183 </ b> H of the perforated reflecting mirror 183, travels to the beam splitter 175, and is divided into four through the condenser lens 178. It is detected by the detector 179.

  Further, the light beam reflected by the reflecting surface around the transmission hole 183H of the perforated reflector 183 is also superimposed on the quadrant detector 179 and incident. When the alignment adjustment of the lens holding flange 182 and the perforated reflecting mirror 183 with respect to the convex mirror 170 (two-axis tilt adjustment of the lens holding flange 182) becomes ideal, all the optical power detected by each light receiving element of the quadrant detector 179 is obtained. Will be equal.

<Step ST4: Install refractive optical lens on lens holding flange>
The hole reflecting mirror 183 is removed from the lens holding flange 182 in an ideal alignment state, and a refractive optical lens (projection optical means, refractive optical unit) 184 is installed instead. The optical lens 178 and the quadrant detector 179 are removed (FIG. 87).

<Step ST5: Projecting Micromirror Device Image onto Jig Screen>
In FIG. 88, a micromirror device (transmission means, image information providing section) 185 is installed at a predetermined position, and the micromirror device 185 is irradiated with light from an illumination light source system (transmission means, illumination light source section) 186. The light from the illumination light source system 186 obtained image information by the micromirror device 185 is projected onto the jig screen 176 via the refractive optical lens 184, the optical path bending reflector 181 and the convex mirror 170.

  Alignment adjustment of the illumination light source system 186 and the micromirror device 185 (mainly the (1) plane of the micromirror device 185 so that the projected light forms an image on the jig screen 176 at a normal position in the screen surface. (1) and (2) are adjustments consisting of two internal positions, (2) one rotation axis around the normal of the plane, (3) two tilt axes, and (4) one axis movement in the normal direction of the plane. When the positions (3) and (4) are important adjustments for ensuring imaging performance), a series of alignment adjustments are completed.

  As described above, according to the twentieth embodiment, since the reflective convex portion 172 or the reflective concave portion 173 is provided in the vicinity of the optical axis 105 of the front surface of the convex mirror 170, in the assembly process of the image display device, the optical system The effect that the alignment adjustment of a component can be performed easily is acquired.

  Further, according to the twentieth embodiment, the parallel light beam transmitted through the transmission hole 176H of the jig screen 176 is reflected by the reflective convex portion 172 (or the reflective concave portion 173), and the reflective convex portion 172 (or the reflective concave portion 173). Step ST1 for matching the forward path and the return path between the optical path 180 and the transmission hole 176H, and the parallel light flux that coincides with the ideal optical axis 180 of the refractive optical lens, the optical path bending reflector 181 and the reflective convex part 172 (or the reflective concave part). 173) in order, and the step ST2 for matching the forward path and the return path between the reflective convex portion 172 (or the reflective concave portion 173) and the optical path bending reflecting mirror 181; and the hole provided in the lens holding flange 182 The parallel light beam incident on the optical path bending reflecting mirror 181 is transmitted through the transmitting hole 183H of the reflecting mirror 183, and is reflected at the periphery of the transmitting hole 183H of the perforated reflecting mirror 183. Step ST3 for matching the traveling direction of the reflected light beam and the light beam that reciprocally reflects the optical path bending reflecting mirror 181 and the reflecting convex portion 172 (or the reflecting concave portion 173), and removing the perforated reflecting mirror 183 from the lens holding flange 182 and refracting it. Instead of installing the optical lens 184 instead of the step ST4, the light from the illumination light source system 186 and the micromirror device 185 through the refractive optical lens 184, the optical path bending reflector 181 and the convex mirror 170 are transmitted on the jig screen 176. Since the step ST5 for forming an image at the position is provided, the effect that the alignment adjustment of the optical system components can be systematically and easily performed in the assembly process of the image display device is obtained.

  Note that, in steps ST1 to ST5, an example in which multi-element alignment adjustment is performed by equalizing the division detector output of the quadrant detector 179 is shown, but in addition to this, the alignment target is set at the position of the quadrant detector 179. It is also possible to make adjustment with a visual observation device that arranges a ground glass jig depicting a cross line or the like and visually observes the condensed light flux on the ground glass jig through an eyepiece or the like.

  Moreover, since the alignment adjustment shown above shows the method of adjusting the angle gap of a reflective surface, it adjusts using the apparatus (for example, autocollimator etc.) which can measure the inclination of a surface using the same jig | tool. You can also

  Of course, the alignment adjustment method shown in the twentieth embodiment is also possible for the convex mirror 104 of the fifteenth embodiment, and the alignment adjustment method shown in the fifteenth embodiment is also possible for the convex mirror 170 of the twentieth embodiment.

Embodiment 21. FIG.
FIG. 89 shows the structure of an image display device according to Embodiment 21 of the present invention. Illustration of an illumination light source system, a plane mirror, a screen, etc. is omitted.
In FIG. 89, 187 is a micromirror device, 188 is a refractive optical lens (projection optical means, refractive optical section) of each embodiment, 189 is a convex mirror (projection optical means, reflection section) of each embodiment, and 190 is refractive. Optical axes 191 and 191 of the optical lens 188 and the convex mirror 189 are lens layers made of glass, synthetic resin, or the like bonded to the front surface 189F of the convex mirror 189.

  In FIG. 89, light (optical image signal) from the micromirror device 187 and the refractive optical lens 188 is first refracted by the incident / exit surface 191Iφ of the lens layer 191 and transmitted through the lens layer 191 before the front of the convex mirror 189. Incident on the surface 189F. The light reflected by the front surface 189F of the convex mirror 189 passes through the lens layer 191 again, is refracted by the incident / exit surface 191Iφ, and travels to a plane mirror or screen (not shown).

  That is, the light exchanged with the convex mirror 189 is optically affected by the shape of the incident / exiting surface 191Iφ of the lens layer 191 and its medium. Therefore, by appropriately designing the surface shape, constituent materials (refractive index, dispersion) and the like of the lens layer 191, it becomes possible to perform optical path control more precisely.

  As described above, according to the twenty-first embodiment, since the lens layer 191 is provided on the front surface 189F of the convex mirror 189, the shape of the incident / exit surface 191Iφ of the lens layer 191 itself and its refractive index / dispersion are appropriately set. By doing so, it is possible to increase the degree of freedom in designing the optical path and to perform more precise light beam control.

Embodiment 22. FIG.
When designing the housing of an image display device, a shape that effectively uses a plurality of slopes is often employed. As a result, the thinned image display device can be felt visually thinner.

  90 is a view showing an overview when the image display device shown in each embodiment is housed in a conventional case, and FIGS. 90A, 90B, and 90C are front views of the case. They are a side view and a top view. The optical system components from the illumination light source system to the convex mirror are not shown.

  In FIG. 90, reference numeral 192 denotes a screen, 193 denotes a lower part of the screen in which an optical system component (not shown) is accommodated, 194 denotes a front part of the casing including the screen 192 and the lower part of the screen 193, and 195 denotes a plane mirror installed in parallel with the screen 192. (Refer to the plane mirror 22 in FIG. 4, Embodiment 1) 196 is a rear portion of the casing in which the plane mirror 195 is housed, and 197U, 197L, and 197R are upper and left and right side slopes that respectively form the casing of the image display device ( 198 is a bottom surface of the image display device.

  In the case of FIG. 90, the height of the housing front part 194 is determined by the vertical installation height of the screen 192 and the height of the screen lower part 193, and the width of the housing front part 194 is determined by the horizontal length of the screen 192. Determined. Further, the height and width of the housing rear portion 196 are determined by the vertical installation height and the horizontal length of the plane mirror 195, respectively (however, the size of the housing rear portion 196 is not limited to the plane mirror 195, and the image display Depending on the configuration of the apparatus, for example, when the plane mirror 195 is not used, it may be changed to a convex mirror).

  Comparing the height and width of the housing front part 194 and the housing rear part 196, since the screen 192 is provided in the housing front part 194, the housing rear part 196 is more than the housing front part 194. It can be said that it is getting smaller. This is also true for general image display devices.

  The housing of the image display device in FIG. 90 is designed so as to surround a space from the large housing front part 194 to the small housing rear part 196 by three inclined surfaces 197U, 197L, 197R and a horizontal bottom surface 198. Here, the housing front part 194 and the housing rear part 196 have shapes in which the corners are cut off from the rectangular parallelepiped by the left and right inclined surfaces 197L and 197R (FIG. 90 (c)).

  In this way, when the image display device is viewed obliquely (in the direction of the block arrow in FIG. 90C), it is possible to see through the rear portion 196 of the housing without being obstructed by anything. It is possible to visually impress the thinning of the image display device. However, as compared with the case where the rectangular parallelepiped housing is multi-configured, the image display device using the inclined surfaces 197U, 197L, and 197R does not come into contact with each other when the screen 192 is kept on the same plane. 14) There is a difficulty that it is difficult to do.

  Now, the image display device of the twenty-second embodiment has been devised as follows in the housing of FIG. 90 with a multi-configuration in mind.

  FIG. 91 is a diagram showing an overview of the casing of the image display device according to the twenty-second embodiment of the present invention, and FIGS. 91 (a), (b), and (c) are a front view, a side view, and a top view, respectively. . Components that are the same as or correspond to those in FIG. 90 are denoted by the same reference numerals.

  91 is characterized in that the corners 194C of the front housing 194 and the corner 196C of the rear housing 196 are not cut off by the inclined surfaces 197L and 197R, and the rear surface of the housing front 194 (the housing rear 196). A parallel surface 194P parallel to the screen 192 is left on the side), and a vertical surface 196V perpendicular to the screen 192 is left on the side of the housing rear portion 196 (FIG. 91C).

By doing in this way, the following effects can be acquired when the image display apparatus is multi-configured while maintaining the visual effect of impressing the above-mentioned thinning.
92 and 93 are diagrams showing a case where the image display apparatus of FIG. 91 is multi-configured by two units, and FIGS. 92 and 93 are a top view and a perspective view, respectively. Components identical or corresponding to those in FIGS. 90 and 91 are given the same reference numerals. In this multi-configuration, the top and bottom of the two image display devices are connected to be adjacent to each other, and a large image is displayed in the horizontal direction.

  92 and 93, reference numeral 199 denotes a connection member having an L-shaped cross section, which is used for connecting and holding the image display apparatus in a multi-configuration. In the left image display device shown in FIG. 92 (a), the parallel surface 194P on the right side of the image display device and the end surface (first end surface) 199A of the connection member 199 are connected to each other, and also on the right side of the image display device. A certain vertical surface 196V is connected to the end surface (second end surface) 199B of the connection member 199 (FIG. 92B). Also on the left side of the right image display device in FIG. 92 (a), another connection member 199 is connected in the same manner, and the two connection members 199 are connected by the connection surfaces 199C.

  Since the end surfaces 199A and 199B are orthogonal to each other and have approximately the same area as the parallel surfaces 194P and 196V, and the end surface 199B and the connection surface 199C are parallel to each other, they are stored in a rectangular parallelepiped housing. In the same manner as the multi-configuration of the image display device, the multi-configuration of the image display device can be obtained with high accuracy, and the installation work efficiency can be improved.

  This effect is due to the provision of the parallel surface 194P and the orthogonal surface 196V on the housing of the image display device so that the connection member 199 can be used. In the case of the housing of FIG. 90, the slope 197L. , 197R acts in a direction in which the force applied to the connecting member is shifted, the same effect cannot be easily obtained.

  Further, holes 199H are provided through the connection surface 199C and the back surface 199D of the connection member 199, and the space formed by the connection member 199 and the inclined surfaces 197L and 197R is used to exchange exhaust / exhaust heat and cables. Etc. can also be performed through the hole 199H.

  At this time, exhaust / exhaust heat and cables are output from the inclined surfaces 197L and 197R outside the housing of the image display device. When the cables are exchanged from the inclined surfaces 197L and 197R through the hole 199H, the rear surface of the image display device becomes a perfect plane, and the rear surface of the image display device can be brought into close contact with, for example, the wall surface of the room.

  Note that the vertical height of the connecting member 199 is not particularly limited, and is usually equal to or lower than the height of the image display device.

  FIG. 94 is a diagram showing a case where four image display apparatuses are multi-configured, and FIGS. 94A and 94B are a front perspective view and a rear perspective view, respectively. The same reference numerals as those in FIGS. 90 to 93 denote the same components. The multi-configuration here is to prepare two sets of two image display devices that are adjacently connected with the same top and bottom, reverse the top and bottom of one set and place it on the top of the other set, both vertically and horizontally A large image is displayed.

  In the case of FIG. 94, exhaust / exhaust heat and cables may be passed through a space formed by the inclined surfaces 197U of the upper and lower image display devices. Also in this case, the image display device can be completely brought into close contact with the wall surface of the room. In addition, by arranging the connection of the upper and lower image display devices so that the end surface of the connecting member 199 on the inclined surface 197U side is in contact, the arrangement of the upper and lower image display devices can be set accurately and easily in a short time. The height of the connection member 199 is the same as the height of the image display device so that the third end surface of the connection member 199 can be brought into contact with each other so that the top and bottom can be connected to each other, and the third end surface is formed perpendicular to the screen (third). Is perpendicular to both end surfaces 199A and 199B).

  As described above, according to the twenty-second embodiment, the front case 194 provided on the bottom surface 198 and provided with the screen 192 and the rear case 196 provided on the bottom surface 198 and housing the plane mirror 195 are provided. And slopes 197U, 197L, 197R provided between the front housing 194 and the rear housing 196, and a parallel surface 194P parallel to the screen 192 is provided on the rear housing 196 side of the front housing 194. In addition, since the slope 197L and the slope 197R are formed so as to leave the vertical surface 196V perpendicular to the screen 192, the image display device can be multi-configured with high accuracy and the installation work efficiency can be improved. Is obtained.

  Further, according to the twenty-second embodiment, the end surface 199A connected to the parallel surface 194P on either the left or right side of the image display device, the end surface 199B connected to the vertical surface 196C on the same side as the parallel surface 194P, and the end surface Since the connection member 199 having a connection surface 199C parallel to 199B is connected to the connection surface 199C of the connection member 199 connected to another image display device, the image display device housed in a rectangular parallelepiped housing As in the case of multi-configuration, the image display apparatus can be multi-configured with high accuracy and the installation work efficiency can be improved.

  Furthermore, according to the twenty-second embodiment, exhaust / heat exhaust or cables are passed from the inside of the housing of the image display device to the outside through the slope 197U, slope 197L and slope 197R. The effect that the image display device can be brought into close contact with each other is obtained. In a state where the back surface is attached to the wall and the upper and lower portions are opened, the triangular prism region surrounded by the connecting member 199 and the inclined surface 197R (197L) can be used as a heat exhaust duct in the vertical direction. With this structure, an effect similar to that of the ents can be expected, and the exhaust heat effect can be improved.

  In each of the embodiments described above, the case where the micromirror device is used as the light spatial modulation element has been described. However, an image display apparatus may be configured by using liquid crystal as the light spatial modulation element. Compared with a conventional image display device, a thinner image display device can be configured.

  Further, as already described in the first embodiment, the present invention can naturally be applied to various types of spatial light modulation elements other than the micromirror device and the liquid crystal, and the image display apparatus is configured to be thin. The effect that can be done can be demonstrated.

  Further, as shown in FIGS. 3 and 13 and the like, in the present invention, the entire optical system is configured in a rotationally symmetrical manner so that the optical axes of the refractive optical lens and the convex mirror are shared. If the optical axis is not shared, considering that an asymmetry with respect to the optical axis occurs, the refractive optical lens and the convex mirror can be easily manufactured by rotational molding by sharing the optical axis. The effect that the alignment can be easily adjusted is also obtained.

It is a figure which shows the structure of the image display apparatus by Embodiment 1 of this invention. It is a figure which illustrates notionally the operation | movement which the barrel type distortion aberration of a refractive optical lens correct | amends the pincushion type distortion aberration of a convex mirror. It is the figure which showed notionally the method of calculating | requiring the image when light is reflected by a convex mirror or a plane mirror through a non-aberration refractive optical lens by optical path tracking. It is a figure which shows the structure of the image display apparatus by Embodiment 1 of this invention which added the plane mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 2 of this invention. It is the figure which expanded the convex mirror and the Fresnel mirror. It is a figure which compares the difference in the distortion aberration of a convex mirror and a Fresnel mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 3 of this invention. It is the figure which expanded the optical element. It is a figure which shows the incident optical path in the inside of an optical element. It is the figure which expand | deployed the optical path in the optical element turned up by the reflective surface in one direction. It is the figure which expanded the optical element. It is a figure which shows the structure of the image display apparatus by Embodiment 4 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 4 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 4 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 4 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 5 of this invention. It is a figure which shows the mode of the change of the power with respect to ratio of the Abbe number of a positive lens and a negative lens. It is a figure explaining the under field curvature generated with an aspherical convex mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 6 of this invention. It is the figure which applied the aspherical surface to the place where the light was gathered, and the place where the light was scattered. It is a figure which shows an example of the numerical calculation result of FIG. It is a figure which shows the structure of the image display apparatus by Embodiment 7 of this invention. It is a figure for demonstrating the effect of the image display apparatus of FIG. It is a figure for demonstrating the effect of the image display apparatus of FIG. It is a figure which shows the structure of the image display apparatus by Embodiment 8 of this invention. It is a figure which shows the structure of a retro optical system. It is a figure which shows the numerical data of numerical Example 8A. It is a figure which shows the structure of numerical example 8A. It is a figure which shows the numerical data of numerical Example 8B. It is a figure which shows the structure of numerical example 8B. It is a figure which shows the numerical data of Numerical Example 8C. It is a figure which shows the structure of numerical example 8C. It is a figure which shows the numerical data of numerical Example 4A. It is a figure which shows the structure of numerical Example 4A. It is a figure which shows the numerical data of numerical Example 4B. It is a figure which shows the structure of numerical Example 4B. It is a figure which shows the numerical data of numerical example 7A. It is a figure which shows the structure of numerical example 7A. It is a figure which shows the relationship between a back side focal distance, an entrance pupil position, and a refractive optical lens. It is a figure which shows the structure of the image display apparatus by Embodiment 9 of this invention. It is a figure for demonstrating the arrangement conditions of an optical path bending reflective mirror. It is a figure which shows the holding mechanism holding a refractive optical lens, an optical path bending reflective mirror, and a convex mirror. It is a figure for demonstrating the arrangement conditions of an optical path bending reflective mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 11 of this invention. It is a figure which shows numerical example 11A of this Embodiment 11. FIG. It is a figure which shows the imaging relationship of a general optical system. It is a figure which shows the example of the optical system with which the image surface curved. It is a figure which shows the structure of the image display apparatus by Embodiment 13 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 14 of this invention. It is a figure which shows the image display apparatus at the time of using with a multi structure. It is a figure which shows the numerical data of Numerical Example 14A. It is a figure which shows the structure of numerical example 14A. It is a figure which shows the numerical calculation result of the distortion aberration in Numerical Example 14A. It is a figure which shows the numerical calculation result of the distortion aberration in Numerical Example 4A. It is a figure which shows the structure of the image display apparatus by Embodiment 15 of this invention. It is a figure for demonstrating the shape change of the thickness direction of the convex mirror with respect to a temperature change. It is a figure which shows the alignment adjustment method using a convex mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 16 of this invention. It is a figure which shows the relationship between the thickness of a cover glass, and the thickness of compensation glass. It is a figure which shows the numerical data of numerical example 16A. It is a figure which shows the structure of numerical example 16A. It is a figure which shows the structure of the image display apparatus using a plane mirror and an optical path bending reflective mirror. It is a figure which shows the structure of the image display apparatus by Embodiment 17 of this invention. It is a figure which shows the cross section of the image display apparatus by A-A 'and B-B' plane orthogonal to a screen, respectively. It is a figure which shows the state of the illumination light source system in which the optical axis inclined. It is a figure which shows the various utilization forms of an image display apparatus. It is a figure which shows the structure of the image display apparatus by Embodiment 17 of this invention. It is a figure which shows the adjustment stand provided with the accommodation hole which accommodates a 3rd optical path bending reflective mirror. It is a figure which shows the structure of the aspherical convex mirror applied to the image display apparatus by Embodiment 18 of this invention. It is a figure for demonstrating operation | movement of the convex mirror which thermally expands by a temperature change. It is a figure for demonstrating deviation | shift Δ ((theta)) of an optical axis when a convex mirror rotates only angle (theta) centering | focusing on the 1st screw retaining part of eccentric distance EXC. It is a figure which shows the structural variation of the convex mirror which gave the temperature change countermeasure. It is a figure which shows the structural variation of the convex mirror for temperature change countermeasures applied to the image display apparatus at the time of upside down. It is a figure which shows the structure of the image display apparatus by Embodiment 19 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 19 of this invention. It is a figure which shows the structure of the image display apparatus by Embodiment 19 of this invention. It is a figure which shows the analysis method of the focus information of a control unit. It is a figure which shows the structure of the image display apparatus by Embodiment 19 of this invention. It is a figure which shows an example which compensates a focus shift | offset | difference by moving the some lens group of a refractive optical lens. It is a figure which shows the structure of the image display apparatus by Embodiment 19 of this invention. It is a figure which shows the structure of the convex mirror applied to the image display apparatus by Embodiment 20 of this invention. It is a figure which shows the flowchart of the alignment adjustment method by Embodiment 20 of this invention. It is a figure which shows a mode that an optical system component is arrange | positioned sequentially according to the alignment adjustment method. It is a figure which shows a mode that an optical system component is arrange | positioned sequentially according to the alignment adjustment method. It is a figure which shows a mode that an optical system component is arrange | positioned sequentially according to the alignment adjustment method. It is a figure which shows a mode that an optical system component is arrange | positioned sequentially according to the alignment adjustment method. It is a figure which shows a mode that an optical system component is arrange | positioned sequentially according to the alignment adjustment method. It is a figure which shows the structure of the image display apparatus by Embodiment 21 of this invention. It is a figure which shows the external appearance at the time of accommodating the image display apparatus shown in each embodiment in the conventional housing | casing. It is a figure which shows the external appearance of the housing | casing of the image display apparatus by Embodiment 22 of this invention. It is a figure which shows the case where two or more image display apparatuses are comprised. It is a figure which shows the case where two or more image display apparatuses are comprised. It is a figure which shows the case where the image display apparatus is comprised by 4 units | sets. It is a figure which shows the structure of the conventional image display apparatus. It is a figure which shows the structure of the conventional image display apparatus which added the plane mirror.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Light-emitting body (transmission means, illumination light source part), 12 Parabolic reflector (transmission means, illumination light source part), 13 Condensing lens (transmission means, illumination light source part), 14 Micromirror device (transmission means, reflection type image) Information providing unit), 15 refractive optical lens (refractive optical unit), 16 convex mirror (reflecting unit), 17 projection optical system (projection optical unit), 18 screen (display unit), 19 refractive optical lens, 20 optical axis, 21 plane mirror , 22 plane mirror, 23 refractive optical lens (refractive optical part), 24 Fresnel mirror (reflective part), 25 projection optical system (projection optical means), 27 optical axis, 28 refractive optical lens (refractive optical part), 29 optical element ( (Reflecting part), 30 projection optical system (projection optical means), 31 low dispersion glass (low dispersion medium), 32 boundary surface, 33 high dispersion glass (high dispersion medium), 34 reflection surface , 35 optical element, 36 high dispersion glass, 37 boundary surface, 38 low dispersion glass, 39 reflective surface, 40 refractive optical lens (projection optical means, refractive optical part), 41 aspherical convex mirror (projection optical means, reflective part), 42 aspheric lens (projection optical means, refractive optical part), 43 spherical convex mirror (projection optical means, reflection part), 44 optical axis, 45 aspheric convex mirror (projection optical means, reflection part), 46 aspheric convex mirror (projection optics) Means, reflection part), 47 aspherical lens (projection optical means, refractive optical part), 48 refractive optical lens (projection optical means, refractive optical part, Petzval sum compensation lens), 48A positive lens, 48B negative lens, 49 refractive optical Lens, 50 optical axes, 51 plane, 52 image plane, 53 image plane, 54 refractive optical lens (projection optical means, refractive optical section, field curvature compensation lens), 55 aspherical surface Lens (projection optical means, refractive optical part, aspherical optical element), 56A, 56B Aspherical lens (projection optical means, refractive optical part, aspherical optical element), 57 Aspherical convex mirror (projection optical means, reflective part) , Aspherical optical element), 58 refractive optical lens (projection optical means, refractive optical part), 58z refractive optical lens, 59 optical path bending reflector (optical path bending means), 60 convex mirror (projection optical means, reflective part) , 61 Optical axis, 62 Retro optical system (projection optical means, refractive optical part), 63 Refractive optical lens (projection optical means, refractive optical part), 64 Aspherical convex mirror (projection optical means, reflective part), 65, 66 Refraction Optical lens, 67, 68 refractive optical lens, 69 convex mirror, 70 optical axis, 71 marginal ray, 72 negative lens, 73 optical axis, 74 holding mechanism, 75 reflected light beam, 76 refractive optical Lens (refractive optical unit), 77 convex mirror, 78 optical axis, 79 marginal ray, 80 positive lens, 81 incident side lens group, 82 output side lens group, 83 refractive optical lens (projection optical means), 84 convex mirror (projection optical means) ), 85 imaging plane, 86A, 86B imaging position, 87 refractive optical lens, 88 convex mirror, 89 image plane, 90A, 90B imaging position, 91 refractive optical lens (refractive optical section), 92, 93 convex mirror, 94 light Axis, 95, 96 exit light, 97, 98 exit pupil, 99 exit light, 100, 100A to 100F screen, 101, 101A to 101F optical axis, 102, 102A to 102F maximum range, 103A, 103B refractive optical lens (refractive optics) Part), 104 convex mirror (reflecting part), 104O convex mirror, 104C non-reflective part, 104F, 104F ' Lont surface, 104R, 104R ′ rear surface, 104L low reflection surface, 104H high reflection surface, 105 optical axis, 106 rays, 106P reflection point, 107 laser, 108 isolator, 109 half mirror, 110 detector, 110A, 110B, 110C , 110D light receiving element, 111, 112 forward path, return path laser beam, 113 virtual optical axis, 114 cover glass (transmitting means), 115 compensation glass (transmitting means), 116 image display device, 117 lower screen, 118 bottom surface, 119 rays , 120 rays, 121, 122 line segments, S space (arrangement space), 123, 123A, 123B illumination light source system (transmission means, illumination light source section, main part of condensing optical system), 124, 124B color wheel (transmission means, Main part of condensing optical system), 125, 125B Rator (transmitting means, main part of condensing optical system), 126, 126B Relay lens (transmitting means, main part of condensing optical system), 127, 127B Second optical path bending reflector (second optical path bending means) , 128 Third optical path bending reflector (third optical path bending means), 129 Field lens (transmitting means), 130, 130A, 130B Optical axis, 131 Extra space, 132 Adjustment table, 133 Storage hole, 134 Convex mirror (Projection optical means, reflecting portion), 134O convex mirror, 134F front surface, 134R rear surface, 135 optical axis, 135P convex mirror apex, 136 first screw retaining portion, 136H screw hole, 137 second screw retaining portion, 137H screw Hole, 138 third screw retaining portion, 138H screw hole, 139 taper screw, 139W washer, 139N nut, 140 convex mirror mounting mechanism (reverse Part mounting mechanism), 141 straight screw, 141W washer, 141N nut, 142 convex mirror mounting mechanism (reflecting part mounting mechanism), 143 spring, 144 concave part, 145 cylindrical support, 146 convex part, 146A, 146B spring retaining part, 147 V Groove support, 148 micromirror device (transmitting means, image information providing section), 149 refractive optical lens (projection optical means, refractive optical section), 149A, 149B, 149C lens, 150 optical axis, 151 optical base (holding mechanism) 152, 153 Slide support column, 154, 155 Mounting plate, 156 Piezoelectric element, 157 Gear support column, 157G Gear mechanism, 158, 159 Temperature sensor, 160 Heating / cooling device, 161 Control unit, 162 Convex mirror (projection optical means, reflection) Part), 163 plane mirror, 16 Screen (display means), 165 image display area, 166 non-image display area, 167 small reflector, 168 CCD element, 169 fixed support column, 170 convex mirror (projection optical means, reflector), 170O convex mirror, 171 optical axis, 172 Reflective convex portion, 173 reflective concave portion, 174 laser light source, 175 beam splitter, 176 jig screen (jig display means), 176H transmission hole (first transmission hole), 177 optical base (holding mechanism), 178 condenser lens 179 Quadrant detector, 180 optical axes, 181 optical path bending reflector, 182 lens holding flange, 183 perforated reflector, 183H transmission hole (second transmission hole), 184 refractive optical lens (projection optical means, refraction) Optical unit), 185 micromirror device (transmission means, image information providing unit), 186 Illumination light source (Transmission means, illumination light source section), 187 Micromirror device (transmission means, image information providing section), 188 Refractive optical lens (projection optical means, refractive optical section), 189 Convex mirror (projection optical means, reflection section), 189F Front Surface, 190 optical axis, 191 lens layer, 191 Iφ entrance / exit surface, 192 screen (display means), 193 lower screen, 194 front case, 194C corner, 194P parallel surface, 195 plane mirror, 196 rear case, 196C corner, 196V vertical surface, 197U, 197L, 197R slope (upper slope, left slope, right slope), 198 bottom face, 199 connecting member, 199A, 199B end face (first and second end faces), 199C connecting face, 199D back face.

Claims (12)

A light emitting body that emits light, a spatial light modulation element that modulates and emits incident illumination light according to image information, and a condensing unit that guides light emitted from the light emitting body to the spatial light modulation element and makes it incident as illumination light transmission means for transmitting the optical image signal is composed, the image information given to the illumination light and a,
Projection optical means for projecting the optical image signal , comprising: a reflection unit that reflects the optical image signal; and a refractive optical unit that corrects the aberration of the reflection unit and projects the optical image signal onto the reflection unit When,
Via the projection optical means by receiving the optical image signal and display means for displaying an image based on the image information,
The optical axis of the upper Symbol projection optical hand stage image display apparatus characterized by being arranged at a position deviated from the display means.   At least a part of the transmission means is disposed in a space on the light receiving surface side of the display means and on one side of the optical axis and that does not block the optical image signal reflected by the reflecting portion. The image display device according to claim 1. A plane mirror that reflects the optical image signal from the projection optical means to the display means;
The light receiving surface of the display means and the reflecting surface of the plane mirror are in a parallel relationship, and have a bottom surface orthogonal to the reflecting surface of the plane mirror and the light receiving surface of the display means,
A first point that is present on the bottom of the quadrangular image displayed on the display means and is furthest away from the center of the image, and a second point on the plane mirror on which light rays toward the first point are reflected. , The third point on the reflecting part where the light beam directed toward the second point is reflected, the first point, the second point, and the third point as a method of the bottom surface From the light emitter and a part of the light collecting means to the pentahedron-shaped arrangement space having the fourth point, the fifth point, and the sixth point, which are points projected on the bottom surface from the line direction, as vertices The image display apparatus according to claim 1, wherein a main part of the condensing optical system is arranged.   4. The projection optical unit includes a first optical path bending unit that reflects an optical image signal from the refractive optical unit to the reflection unit. The image display device described.   5. The image display device according to claim 4, wherein the first optical path bending means bends the optical axis direction of the refractive optical unit within a horizontal plane including the optical axis of the reflecting unit.   5. The image display device according to claim 4, wherein the first optical path bending means is a reflecting mirror or a prism element.   5. The refracting optical unit includes second optical path bending means for reflecting an optical image signal from the first lens means to the second lens means. The image display device according to claim 1.   8. The image display device according to claim 7, wherein the second optical path bending means is a reflecting mirror or a prism element.   9. The image display device according to claim 1, wherein the reflection portion has a shape obtained by cutting off a non-reflective portion that does not reflect an optical image signal to the display unit. 10.   4. An image display device according to claim 3, wherein the optical axis of the main part of the condensing optical system is arranged in parallel to the light receiving surface and the bottom surface of the display means.   4. The image display according to claim 3, wherein the optical axis of the main part of the condensing optical system is installed in parallel to the light receiving surface of the display means and is inclined at a predetermined angle with respect to the bottom surface. apparatus.   A second prism element that mediates a light beam emitted from the main part of the condensing optical system and incident on the spatial light modulation element and a light beam emitted from the spatial modulation element and incident on the refractive optical part; The image display device according to any one of claims 3, 10, and 11.

Images